Methods and systems for controlling mold temperatures

ABSTRACT

Disclosed is a preferred mold design for producing plastic, molded preforms, which may be blow-molded into a container of a final, desired shape. A preferred mold includes a temperature control system for maintaining the preform mold at a desired temperature. The temperature control system can pass fluid through channels within the preform mold to cool plastic that is injected into the preform mold. In some arrangements, a mold comprises a neck finish mold, the neck finish mold comprising high heat transfer material positioned to transfer heat away from melt within a mold cavity of the mold.

RELATED APPLICATIONS

This application claims the priority benefit under 35 U.S.C. § 119(e) ofthe provisional application 60/578,501, filed Jun. 10, 2004, and60/654,554, filed Feb. 18, 2005, which are hereby incorporated byreference in their entireties.

BACKGROUND OF THE INVENTIONS

1. Field of the Inventions

The inventions relate to molds for producing articles. Morespecifically, these inventions relate to methods and systems forcontrolling mold temperatures.

2. Description of the Related Art

The use of plastic containers as a replacement for glass or metalcontainers in the packaging of beverages has become increasinglypopular. The advantages of plastic packaging include lighter weight,decreased breakage as compared to glass, and potentially lower costs.The most common plastic used in making beverage containers today is PET.Virgin PET has been approved by the FDA for use in contact withfoodstuffs. Containers made of PET are transparent, thin-walled,lightweight, and have the ability to maintain their shape bywithstanding the force exerted on the walls of the container bypressurized contents, such as carbonated beverages. PET resins are alsofairly inexpensive and easy to process.

Most PET bottles are made by a process that includes the blow-molding ofplastic preforms, which have been made by processes including injectionand compression molding. For example, in order to increase thethrough-put of an injection molding machine, and thereby decrease thecost of each individual preform, it is desirable to reduce the cycletime for each injection and cooling cycle. However, the injected preformmust cool sufficiently to maintain its molded dimensions before it isremoved from the injection mold. Therefore, it would be desirable toutilize a cooling system that can rapidly cool the injected preform.Typically, the temperature of the mold is controlled by pumping cooledwater through passages which are within the mold. The temperature of themold is thus controlled by the temperature of the water flowing throughthe water passages. The water typically flows continuously throughoutthe molding operation and may cause condensation to form on the mold.For example, when the mold is cooled by utilizing chilled water, themoisture in the air surrounding the mold can condense, thereby formingcondensation on the molding surfaces. The condensation may interferewith the molding operation by reducing preform production and decreasingpreform quality. As a result, the potential of mold cooling systems hasnot been realized.

SUMMARY OF THE INVENTIONS

In some embodiments, a mold is configured to mold an article. The moldcan have a mold cavity for receiving and molding moldable material. Themold can be configured to mold a single article or a plurality ofarticles.

In one embodiment, an injection mold comprises a core section having acore surface and a cavity section having a cavity surface. The injectionmold further comprises a plurality of fluid channels proximate to thecavity surface and a valve proximate to the cavity surface. The valve isconfigured to allow fluid to flow into the fluid channels while causinga pressure drop of the fluid across the valve to cool the cavity surfaceas the fluid passes through the fluid channels and cools the cavitysurface.

In some embodiments, a mold comprises a cavity section and a coresection. The core section is configured to mate with the cavity sectionto form a mold cavity and comprises a core that defines an internalsurface of the mold cavity. The core is configured to receiverefrigerant to control the temperature of the core. In some embodiments,at least a portion of the refrigerant is vaporized within the core. Insome embodiments, at least a portion of the refrigerant is vaporizedwithin the core by passing through one or more pressure reducingelements positioned within the core.

In some embodiments, a mold temperature control assembly comprises acavity section and a core section. The core section is configured tomate with the cavity section to form a mold cavity and comprises a corethat defines an internal surface of the mold cavity. A tube within thecore extends from the proximal end of the core to an expansion valve atthe distal end of the core. The expansion valve is configured to receivefluid that comprises substantially liquid from the tube and isconfigured to deliver fluid comprising substantially gas to a channelwithin the core. In some embodiments, gas is at a temperature less thantemperature of the internal surface of the mold cavity.

In another embodiment, a mold temperature control assembly comprises acavity section, a plurality of fluid channels, and a valve system. Thecavity section defines a cavity surface. The plurality of fluid channelssurrounds a portion of the cavity surface, and a portion of the fluidchannels is within the cavity section. The valve system is locatedupstream of the fluid channels and is configured to receive fluid at afirst temperature and deliver the fluid at a second temperature, whichis less than the first temperature, to the fluid channels to cool thecavity surface. In some embodiments, the valve system comprises a singlepressure reducing element. In some embodiments, the valve systemcomprises a plurality of pressure reducing elements.

In one embodiment, a method of controlling the temperature of a moldcomprises providing a core section having a core mold surface and acavity section having a cavity mold surface and channels. Fluid isdelivered at a first temperature to a valve system within the cavitysection, the valve system outputs the fluid at a second temperature,which is less than the first temperature and the temperature of thecavity mold surface, to the channels to cool the cavity mold surface. Insome embodiments, the valve system comprises one or more pressurereducing elements.

In some embodiments, a mold is configured to mold an article. In someembodiments, the mold is configured to produce preforms, containers,trays, closures, and the like. In some embodiments, the mold comprises atemperature control element configured to affect the temperature of themold. The temperature control element can comprise one or more of thefollowing: fluid passageways, channels, temperature control rod (e.g.,heating/cooling rods), and heater (e.g., resistance heater). The moldcan be an intrusion mold, compression mold, blow mold, injection mold,or other type of molding system for forming articles. In someembodiments, the blow mold can be a stretch blow mold for stretch blowmolding a preform. In some embodiments, the blow mold can be anextrusion blow mold.

In some embodiments, a mold comprises a core section that has a coresurface. A cavity section has a cavity surface. A mold cavity is definedby the core section and the cavity section when the mold is in a closedposition. In some embodiments, a temperature control element, such as afluid channel, is disposed within one of the core section and the cavitysection. A pressure reducing device is configured to receive andvaporize at least a portion of a refrigerant. In some embodiments, thepressure reducing device is in fluid communication with the fluidchannel. The one of the core section and the cavity section compriseshigh heat transfer material. The high heat transfer material ispositioned between the fluid channel and the mold cavity. In someembodiments, the mold does not comprise high heat transfer material.

In some embodiments, a molding system comprises a first mold section anda second mold section movable between an open position and a closedposition. A mold cavity is defined between the first mold section andthe second mold section when the first mold section and the second moldsection occupy the closed position. At least one of the first moldsection and the second mold section comprises high heat transfermaterial and at least one fluid channel. A fluid source is in fluidcommunication with the at least one fluid channel. The fluid sourcecontains a working fluid (e.g., a refrigerant). A pressure reducingelement is in fluid communication with the at least one fluid channeland the fluid source. The pressure reducing element is configured toreduce a pressure of the refrigerant from the fluid source to a secondpressure equal to or less than a vaporization pressure of therefrigerant. In some embodiments, the molding system comprises aplurality of pressure reducing elements.

In some embodiments, one or more temperature sensors are interposedbetween a molding surface of a mold and at least temperature controlelement of the mold. In some embodiments, one or more temperaturesensors are positioned somewhat proximate to the mold surface. Thetemperature sensors can accurately measure the temperature of the mold.In some embodiments, a controller is in communication with thetemperature sensor. The controller can be configured to selectivelycontrol the operation of a valve (e.g., a pressure reducing element) inresponse to a signal from the temperature sensor. In some embodiments, amold has a plurality of temperature sensors. The sensors can bepositioned at various locations within the material forming the mold.

In some embodiments, a mold for molding an article comprises a cavitysection and a core section. The core section is configured to mate withthe cavity section to form a mold cavity. The core section comprises acore that defines an internal surface of the mold cavity. A tube isdisposed within the core. The tube extends from a proximal end of thecore to a pressure reducing valve at a distal end of the core. Thepressure reducing valve is configured to receive fluid from the tube andto deliver at least partially vaporized fluid to a channel within thecore. The partially vaporized fluid in the core is at a temperature lessthan a temperature of the internal surface of the mold cavity when meltfills the mold cavity.

In some embodiments, a mold assembly comprises a core section and acavity section. The cavity section defines a cavity surface that isconfigured to mold at least a portion of an article. The cavity sectioncooperates with the core section to form a space. A plurality of fluidchannels surrounds a portion of the cavity surface. The plurality offluid channels is positioned within a portion of the cavity section andhas a high thermal conductivity. A valve system is located upstream ofthe fluid channels. The valve system receives fluid at a firsttemperature and delivers the fluid at a second temperature, which isless than the first temperature, to the plurality of fluid channels. Insome embodiments, the fluid is a cryogenic fluid. In some embodiments,the cryogenic refrigerant is a high temperature range cryogenic fluid.In some embodiments, the cryogenic refrigerant is a mid temperaturerange cryogenic. In some embodiments, the cryogenic refrigerant is a lowtemperature range cryogenic fluid.

In some embodiments, a mold is configured to utilize a working fluid. Insome embodiments, the working fluid is a refrigerant. In someembodiments, the working fluid is a cryogenic fluid. In someembodiments, the fluid is a cryogenic fluid. In some embodiments, thecryogenic refrigerant is a high temperature range cryogenic fluid. Insome embodiments, the cryogenic refrigerant is a mid temperature rangecryogenic. In some embodiments, the cryogenic refrigerant is a lowtemperature range cryogenic fluid.

In some embodiments, a method of controlling the temperature of a moldfor molding a preform comprises providing a core section having a coremold surface. A cavity section having a cavity mold surface and fluidchannels is provided. A refrigerant is delivered at a first temperatureto a valve system. The valve system outputs the refrigerant at a secondtemperature, which is less than the first temperature and a temperatureof the cavity mold surface. The refrigerant is passed from the valvesystem through at least one of the cavity section and the core sectionto reduce the temperature of polymer material disposed between the coremold surface and the cavity mold surface. In some embodiments, thepolymer material is in the shape of a preform or closure.

In some embodiments, a molding system comprises a first mold section anda second mold section movable between an open position and a closedposition. A mold cavity is defined between the first mold section andthe second mold section when the first mold section and the second moldsection occupy the closed position. The mold cavity has a shape of apreform. A neck finish mold is interposed between the first mold sectionand the second mold section. The neck finish mold has a neck moldingsurface configured to mold a portion of melt disposed in the moldcavity. The neck finish mold comprises high heat transfer material and atemperature control element configured to selectively control thetemperature of the neck molding surface. In some embodiments, the highheat transfer material is positioned between the neck molding surfaceand the temperature control element. At least a portion of thetemperature control element may or may not be embedded in the high heattransfer material.

In some embodiments, a neck finish mold is configured to mold at least apotion of an article. In some embodiments, the neck finish moldcomprises a high heat transfer material. The high heat transfer materialmay or may not form a molding surface that can engage melt injected intoa cavity of a mold. In some embodiments, the neck finish mold is a splitring movable between two or more positions. In some embodiments, theneck finish mold comprises a temperature control element, such as one ormore fluid passageways, heat/cooling rods.

In some embodiments, a mold temperature control system comprises a firstmold section and a second mold section movable between an open positionand a closed position. A mold cavity is defined between the first moldsection and the second mold section when the first mold section and thesecond mold section occupy the closed position. A means for passing arefrigerant through at least one of the first mold section and thesecond mold section for controlling the temperature of moldable materialis positioned within the mold cavity. A means for vaporizing at least aportion of the refrigerant that subsequently passes through the meansfor passing the refrigerant is provided. A means for delivering therefrigerant to the means for vaporizing at least the portion of therefrigerant is provided.

In some embodiments, a method for making a preform comprises providing acavity mold half and a core mold half. The cavity mold half and the coremold half define a space in the shape of a preform. A first material isdeposited into the space. A sufficient amount of refrigerant to reducethe temperature of the refrigerant is vaporized. The refrigerant iscirculated within one of the cavity mold half and the core mold half tocool the first material to form a preform. In some embodiments, themethod further comprises removing the preform from the cavity mold half.The preform is placed into a second cavity mold half. A second materialis injected through a gate of the second cavity mold half into a secondspace defined by the second cavity mold half and the preform to form amultilayer preform. A second fluid is circulated through at least one ofthe second cavity mold half and the core mold half to cool a multilayerpreform.

In some embodiments, a preform comprises a body comprising a wall and anend cap portion. The wall has a dimensionally stable outer layersuitable for demolding the preform and an interior portion adjacent theouter layer that comprises soft warm polymer material. A neck portion isconnected to the body. In some embodiments, the interior portion ispositioned between the dimensionally stable outer layer and a seconddimensionally stable outer layer. The outer layers form an exteriorsurface and an interior surface of the preform. In some embodiments, theheat from the preform is transferred through high heat transfer materialand to a refrigerant. The refrigerant can comprise cryogenic fluid. Insome embodiments, the preform has an eggshell finish.

In some embodiments, a mold apparatus comprises high heat transfermaterial. In some embodiments, the high heat transfer material has athermal conductivity greater than the thermal conductivity of iron. Insome embodiments, the high heat transfer material has a thermalconductivity selected from one of a thermal conductivity greater thanthe thermal conductivity of iron, a thermal conductivity at least twotimes greater than the thermal conductivity of iron, a thermalconductivity at least three times greater than the thermal conductivityof iron, and a thermal conductivity at least four times greater than thethermal conductivity of iron. In some embodiments, the high heattransfer material has a thermal conductivity selected from one of athermal conductivity greater than the thermal conductivity of iron andless than two times the thermal conductivity of iron, a thermalconductivity at least two times greater than the thermal conductivity ofiron and less than three times the thermal conductivity of iron, athermal conductivity at least three times greater than the thermalconductivity of iron and less than four times the thermal conductivityof iron, and a thermal conductivity at least four times greater than thethermal conductivity of iron. In some embodiments, the high heattransfer material comprises hardened copper alloy.

In some embodiments, molding systems can utilize highly conductivealloys and refrigerants. The combination of high heat transfer materialsand refrigerants can provide efficient cooling, or heating, and canminimize cycle time. The high heat transfer materials and refrigerantscan be used to rapidly cool molded articles in the mold. The combinationof high heat transfer materials and refrigerants can provide efficientand rapid heating of the mold, especially when the mold surfaces are ata low temperature. For example, the mold surfaces can be at a lowtemperature at the end of a cooling cycle. In some embodiments, the moldsurfaces can be warmed so that melt can spread easily through a moldcavity of the mold.

In some embodiments, a mold is configured to mold an article. At least aportion of the article can have a hardened outer surface. The outersurface can be in the form of a somewhat eggshell like layer. In someembodiments, substantially the entire exterior surface and/or interiorsurface of an article comprise a hardened outer surface. The interiorportions of the articles can be warm and soft when the preform isdemolded.

In some embodiments, a mold can have one or more mold cavitiesconfigured to receive moldable material. The mold can have one or moreof the following: a core, a cavity section, a gate insert, and a neckfinish mold. These components can be heated or cooled by employing aworking fluid. The working fluid can be a refrigerant. The working fluidcan be used to cool a moldable material positioned within the mold. Whenthe molded article is removed, the working fluid can preheat the moldsurfaces so that moldable material, such as a molten polymer, can spreadeasily through the mold cavity.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a preform as is used as a starting material for making amolded container;

FIG. 2 is a cross-section of the monolayer preform of FIG. 1;

FIG. 3 is a cross-section of a multilayer preform;

FIG. 4 is a cross-section of another embodiment of a multilayer preform;

FIG. 5 is a three-layer embodiment of a preform;

FIG. 6 is a cross-section of a preform in the cavity of a blow-moldingapparatus of a type that may be used to make a container;

FIG. 6A is a cross-section of another embodiment of a blow-moldingapparatus;

FIG. 7 is a side view of one embodiment of a container;

FIG. 8 is a schematic illustration of a temperature control system;

FIGS. 9A-9L are schematic illustrations of temperature control systems;

FIG. 10 is a cross-section of an injection mold of a type that may beused to make a preferred multilayer preform;

FIG. 11 is a cross-section of the mold of FIG. 10 taken along lines11-11;

FIG. 12 is another embodiment of an injection mold of a type that may beused to make a multilayer preform;

FIG. 13 is a cross-section of an injection mold of a type that may beused to make a monolayer preform;

FIGS. 13A-13F are side views of portions of neck finish molds;

FIG. 14 is a cross-section of the mold of FIG. 13 taken along lines14-14;

FIG. 15 is a cutaway close up view of the area of FIG. 13 defined byline 15;

FIG. 16 is a cross-section of an injection mold core having a doublewall neck finish portion;

FIG. 17 is a cross-section of an enhanced injection mold core having ahigh heat transfer base end portion;

FIG. 18 is a cross-section of an injection mold utilizing a combinationof hardened material components and high heat transfer materialcomponents and fluid channels;

FIG. 18A is a cross-section of another injection mold utilizing highheat transfer material;

FIGS. 19 and 20 are two halves of a molding machine to make multilayerpreforms;

FIGS. 21 and 22 are two halves of a molding machine to make forty-eighttwo layer preforms;

FIG. 23 is a perspective view of a schematic of a mold with corespartially located within the molding cavities;

FIG. 24 is a perspective view of a mold with cores fully withdrawn fromthe molding cavities, prior to rotation;

FIG. 25 is a top plan view of a compression molding system for producingpreforms;

FIG. 25A is a top plan view of a compression molding system forproducing multilayer preforms;

FIG. 26 is a cross-sectional view of the compression molding systemtaken along lines 26-26 of FIG. 25;

FIG. 27 is a cross-section of a cavity section of FIG. 26 containing aplug of material;

FIG. 28 is a cross-sectional view of a core section and a cavity sectionin an open position;

FIG. 29 is a cross-sectional view of the core section and the cavitysection in a closed position;

FIG. 29A is a cross-sectional view the core section and the cavitysection of FIG. 29 in a closed position, moldable material is disposedwithin a cavity defined by the core section and the cavity section;

FIG. 30 is a cross-sectional view of a core section and a cavity sectionin a partially open position in accordance with another embodiment;

FIG. 31 is a cross-sectional view of a core section and a cavity sectionin a closed position in accordance with another embodiment;

FIG. 32 is a top plan view of a compression molding system for producingpreforms in accordance with another embodiment;

FIG. 33 is a cross-sectional view of a core section and a cavity sectionof the system of FIG. 32 in a closed position, the core section and thecavity section define a cavity for forming an outer layer of a preform;

FIG. 34 is a cross-sectional view of another core section and the cavitysection of the system of FIG. 32 in a closed position, the core sectionand the cavity section define a space for forming an inner layer of apreform;

FIG. 35 is a cross-sectional view of a compression molding systemconfigured to make a closure; and

FIG. 36 is a sectional view of another cavity section and the coresection of FIG. 35, the core section and the cavity section define aspace for forming an outer layer of a closure.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

All patents and publications mentioned herein are hereby incorporated byreference in their entireties. Except as further described herein,certain embodiments, features, systems, devices, materials, methods andtechniques described herein may, in some embodiments, be similar to anyone or more of the embodiments, features, systems, devices, materials,methods and techniques described in U.S. Pat. Nos. 6,109,006; 6,808,820;6,528,546; 6,312,641; 6,391,408; 6,352,426; 6,676,883; U.S. patentapplication Ser. No. 09/745,013 (Publication No. 2002-0100566); Ser. No.10/168,496 (Publication No. 2003-0220036); Ser. No. 09/844,820(2003-0031814); Ser. No. 10/090,471 (Publication No. 2003-0012904); Ser.No. 10/395,899 (Publication No. 2004-0013833); Ser. No. 10/614,731(Publication No. 2004-0071885), provisional application 60/563,021,filed Apr. 16, 2004, provisional application 60/575,231, filed May 28,2004, provisional application 60/586,399, filed Jul. 7, 2004,provisional application 60/620,160, filed Oct. 18, 2004, provisionalapplication 60/621,511, filed Oct. 22, 2004, and provisional application60/643,008, filed Jan. 11, 2005, U.S. patent application Ser. No.11/108,342 entitled MONO AND MULTI-LAYER ARTICLES AND COMPRESSIONMETHODS OF MAKING THE SAME, filed on Apr. 18, 2005, U.S. patentapplication Ser. No. 11/108,345 entitled MONO AND MULTI-LAYER ARTICLESAND INJECTION METHODS OF MAKING THE SAME, filed on Apr. 18, 2005, U.S.patent application Ser. No. 11/108,607 entitled MONO AND MULTI-LAYERARTICLES AND EXTRUSION METHODS OF MAKING THE SAME, filed on Apr. 18,2005, which are hereby incorporated by reference in their entireties. Inaddition, the embodiments, features, systems, devices, materials,methods and techniques described herein may, in certain embodiments, beapplied to or used in connection with any one or more of theembodiments, features, systems, devices, materials, methods andtechniques disclosed in the above-mentioned patents and applications.

A. Detailed Description of Some Preferred Materials

1. General Description of Preferred Materials

The articles described herein may be described specifically in relationto a particular material, such as polyethylene terephthalate (PET) orpolypropylene (PP), but preferred methods are applicable to many otherthermoplastics, including those of the of the polyester and polyolefintypes. Other suitable materials include, but are not limited to, foammaterials, various polymers and thermosets, thermoplastic materials suchas polyesters, polyolefins, including polypropylene and polyethylene,polycarbonate, polyamides, including nylons (e.g. Nylon 6, Nylon 66,MXD6), polystyrenes, epoxies, acrylics, copolymers, blends, graftedpolymers, and/or modified polymers (monomers or portion thereof havinganother group as a side group, e.g. olefin-modified polyesters). Thesematerials may be used alone or in conjunction with each other. Morespecific material examples include, but are not limited to, ethylenevinyl alcohol copolymer (“EVOH”), ethylene vinyl acetate (“EVA”),ethylene acrylic acid (“EAA”), linear low density polyethylene(“LLDPE”), polyethylene 2,6- and 1,5-naphthalate (PEN), polyethyleneterephthalate glycol (PETG), poly(cyclohexylenedimethyleneterephthalate), polystryrene, cycloolefin, copolymer,poly-4-methylpentene-1, poly(methyl methacrylate), acrylonitrile,polyvinyl chloride, polyvinylidine chloride, styrene acrylonitrile,acrylonitrile-butadiene-styrene, polyacetal, polybutylene terephthalate,ionomer, polysulfone, polytetra-fluoroethylene, polytetramethylene1,2-dioxybenzoate and copolymers of ethylene terephthalate and ethyleneisophthalate.

As used herein, the term “polyethylene terephthalate glycol” (PETG)refers to a copolymer of PET wherein an additional comonomer,cyclohexane di-methanol (CHDM), is added in significant amounts (e.g.approximately 40% or more by weight) to the PET mixture. In oneembodiment, preferred PETG material is essentially amorphous. SuitablePETG materials may be purchased from various sources. One suitablesource is Voridian, a division of Eastman Chemical Company. Other PETcopolymers include CHDM at lower levels such that the resulting materialremains crystallizable or semi-crystalline. One example of PET copolymercontaining low levels of CHDM is Voridian 9921 resin.

In some embodiments polymers that have been grafted or modified may beused. In one embodiment polypropylene or other polymers may be graftedor modified with polar groups including, but not limited to, maleicanhydride, glycidyl methacrylate, acryl methacrylate and/or similarcompounds to improve adhesion. In other embodiments polypropylene alsorefers to clarified polypropylene. As used herein, the term “clarifiedpolypropylene” is a broad term and is used in accordance with itsordinary meaning and may include, without limitation, a polypropylenethat includes nucleation inhibitors and/or clarifying additives.Clarified polypropylene is a generally transparent material as comparedto the homopolymer or block copolymer of polypropylene. The inclusion ofnucleation inhibitors helps prevent and/or reduce crystallinity, whichcontributes to the haziness of polypropylene, within the polypropylene.Clarified polypropylene may be purchased from various sources such asDow Chemical Co. Alternatively, nucleation inhibitors may be added topolypropylene. One suitable source of nucleation inhibitor additives isSchulman.

Optionally, the materials may comprise microstructures such asmicrolayers, microspheres, and combinations thereof. In certainembodiments preferred materials may be virgin, pre-consumer,post-consumer, regrind, recycled, and/or combinations thereof.

As used herein, “PET” includes, but is not limited to, modified PET aswell as PET blended with other materials. One example of a modified PETis “high IPA PET” or IPA-modified PET, which refer to PET in which theIPA content is preferably more than about 2% by weight, including about2-10% IPA by weight, also including about 5-10% IPA by weight. PET canbe virgin, pre or post-consumer, recycled, or regrind PET, PETcopolymers and combinations thereof.

In embodiments of preferred methods and processes one or more layers maycomprise barrier layers, UV protection layers, oxygen scavenging layers,oxygen barrier layers, carbon dioxide scavenging layers, carbon dioxidebarrier layers, and other layers as needed for the particularapplication. As used herein, the terms “barrier material,” “barrierresin,” and the like are broad terms and are used in their ordinarysense and refer, without limitation, to materials which, when used inpreferred methods and processes, have a lower permeability to oxygen andcarbon dioxide than the one or more of the layers. As used herein, theterms “UV protection” and the like are broad terms and are used in theirordinary sense and refer, without limitation, to materials which have ahigher UV absorption rate than one or more layers of the article. Asused herein, the terms “oxygen scavenging” and the like are broad termsand are used in their ordinary sense and refer, without limitation, tomaterials which have a higher oxygen absorption rate than one or morelayers of the article. As used herein, the terms “oxygen barrier” andthe like are broad terms and are used in their ordinary sense and refer,without limitation, to materials which are passive or active in natureand slow the transmission of oxygen into and/or out of an article. Asused herein, the terms “carbon dioxide scavenging” and the like arebroad terms and are used in their ordinary sense and refer, withoutlimitation, to materials which have a higher carbon dioxide absorptionrate than one or more layers of the article. As used herein, the terms“carbon dioxide barrier” and the like are broad terms and are used intheir ordinary sense and refer, without limitation, to materials whichare passive or active in nature and slow the transmission of carbondioxide into and/or out of an article. Without wishing to be bound toany theory, applicants believe that in applications wherein a carbonatedproduct, e.g. a soft-drink beverage, contained in an article isover-carbonated, the inclusion of a carbon dioxide scavenger in one ormore layers of the article allows the excess carbonation to saturate thelayer which contains the carbon dioxide scavenger. Therefore, as carbondioxide escapes to the atmosphere from the article it first leaves thearticle layer rather than the product contained therein. As used herein,the terms “crosslink,” “crosslinked,” and the like are broad terms andare used in their ordinary sense and refer, without limitation, tomaterials and coatings which vary in degree from a very small degree ofcrosslinking up to and including fully cross linked materials such as athermoset epoxy. The degree of crosslinking can be adjusted to providethe appropriate degree of chemical or mechanical abuse resistance forthe particular circumstances. As used herein, the term “tie material” isa broad term and is used in its ordinary sense and refers, withoutlimitation, to a gas, liquid, or suspension comprising a material thataids in binding two materials together physically and/or chemically,including but not limited to adhesives, surface modification agents,reactive materials, and the like.

2. Preferred Materials

In a preferred embodiment materials comprise thermoplastic materials. Afurther preferred embodiment includes “Phenoxy-Type Thermoplastics.”Phenoxy-Type Thermoplastics, as that term is used herein, include a widevariety of materials including those discussed in WO 99/20462. In oneembodiment, materials comprise thermoplastic epoxy resins (TPEs), asubset of Phenoxy-Type Thermoplastics. A further subset of Phenoxy-TypeThermoplastics, and thermoplastic materials, are preferredhydroxy-phenoxyether polymers, of which polyhydroxyaminoether copolymers(PHAE) is a further preferred material. See for example, U.S. Pat. Nos.6,455,116; 6,180,715; 6,011,111; 5,834,078; 5,814,373; 5,464,924; and5,275,853; see also PCT Application Nos. WO 99/48962; WO 99/12995; WO98/29491; and WO 98/14498. In some embodiments, PHAEs are TPEs.

Preferably, the Phenoxy-Type Thermoplastics used in preferredembodiments comprise one of the following types:

-   (1) hydroxy-functional poly(amide ethers) having repeating units    represented by any one of the Formulae Ia, Ib or Ic:-   (2) poly(hydroxy amide ethers) having repeating units represented    independently by any one of the Formulae IIa, IIb or IIc:-   (3) amide- and hydroxymethyl-functionalized polyethers having    repeating units represented by Formula III:-   (4) hydroxy-functional polyethers having repeating units represented    by Formula IV:-   (5) hydroxy-functional poly(ether sulfonamides) having repeating    units represented by Formulae Va or Vb:-   (6) poly(hydroxy ester ethers) having repeating units represented by    Formula VI:-   (7) hydroxy-phenoxyether polymers having repeating units represented    by Formula VII:    and-   (8) poly(hydroxyamino ethers) having repeating units represented by    Formula VIII:    wherein each Ar individually represents a divalent aromatic moiety,    substituted divalent aromatic moiety or heteroaromatic moiety, or a    combination of different divalent aromatic moieties, substituted    aromatic moieties or heteroaromatic moieties; R is individually    hydrogen or a monovalent hydrocarbyl moiety; each Ar₁ is a divalent    aromatic moiety or combination of divalent aromatic moieties bearing    amide or hydroxymethyl groups; each Ar₂ is the same or different    than Ar and is individually a divalent aromatic moiety, substituted    aromatic moiety or heteroaromatic moiety or a combination of    different divalent aromatic moieties, substituted aromatic moieties    or heteroaromatic moieties; R₁ is individually a predominantly    hydrocarbylene moiety, such as a divalent aromatic moiety,    substituted divalent aromatic moiety, divalent heteroaromatic    moiety, divalent alkylene moiety, divalent substituted alkylene    moiety or divalent heteroalkylene moiety or a combination of such    moieties; R₂ is individually a monovalent hydrocarbyl moiety; A is    an amine moiety or a combination of different amine moieties; X is    an amine, an arylenedioxy, an arylenedisulfonamido or an    arylenedicarboxy moiety or combination of such moieties; and Ar₃ is    a “cardo” moiety represented by any one of the Formulae:    -   wherein Y is nil, a covalent bond, or a linking group, wherein        suitable linking groups include, for example, an oxygen atom, a        sulfur atom, a carbonyl atom, a sulfonyl group, or a methylene        group or similar linkage; n is an integer from about 10 to about        1000; x is 0.01 to 1.0; and y is 0 to 0.5.

The term “predominantly hydrocarbylene” means a divalent radical that ispredominantly hydrocarbon, but which optionally contains a smallquantity of a heteroatomic moiety such as oxygen, sulfur, imino,sulfonyl, sulfoxyl, and the like.

The hydroxy-functional poly(amide ethers) represented by Formula I arepreferably prepared by contacting an N,N′-bis(hydroxyphenylamido)alkaneor arene with a diglycidyl ether as described in U.S. Pat. Nos.5,089,588 and 5,143,998.

The poly(hydroxy amide ethers) represented by Formula II are prepared bycontacting a bis(hydroxyphenylamido)alkane or arene, or a combination of2 or more of these compounds, such as N,N′-bis(3-hydroxyphenyl)adipamide or N,N′-bis(3-hydroxyphenyl)glutaramide, with an epihalohydrinas described in U.S. Pat. No. 5,134,218.

The amide- and hydroxymethyl-functionalized polyethers represented byFormula III can be prepared, for example, by reacting the diglycidylethers, such as the diglycidyl ether of bisphenol A, with a dihydricphenol having pendant amido, N-substituted amido and/or hydroxyalkylmoieties, such as 2,2-bis(4-hydroxyphenyl)acetamide and3,5-dihydroxybenzamide. These polyethers and their preparation aredescribed in U.S. Pat. Nos. 5,115,075 and 5,218,075.

The hydroxy-functional polyethers represented by Formula IV can beprepared, for example, by allowing a diglycidyl ether or combination ofdiglycidyl ethers to react with a dihydric phenol or a combination ofdihydric phenols using the process described in U.S. Pat. No. 5,164,472.Alternatively, the hydroxy-functional polyethers are obtained byallowing a dihydric phenol or combination of dihydric phenols to reactwith an epihalohydrin by the process described by Reinking, Barnabeo andHale in the Journal of Applied Polymer Science, Vol. 7, p. 2135 (1963).

The hydroxy-functional poly(ether sulfonamides) represented by Formula Vare prepared, for example, by polymerizing an N,N′-dialkyl orN,N′-diaryldisulfonamide with a diglycidyl ether as described in U.S.Pat. No. 5,149,768.

The poly(hydroxy ester ethers) represented by Formula VI are prepared byreacting diglycidyl ethers of aliphatic or aromatic diacids, such asdiglycidyl terephthalate, or diglycidyl ethers of dihydric phenols with,aliphatic or aromatic diacids such as adipic acid or isophthalic acid.These polyesters are described in U.S. Pat. No. 5,171,820.

The hydroxy-phenoxyether polymers represented by Formula VII areprepared, for example, by contacting at least one dinucleophilic monomerwith at least one diglycidyl ether of a cardo bisphenol, such as9,9-bis(4-hydroxyphenyl)fluorene, phenolphthalein, orphenolphthalimidine or a substituted cardo bisphenol, such as asubstituted bis(hydroxyphenyl)fluorene, a substituted phenolphthalein ora substituted phenolphthalimidine under conditions sufficient to causethe nucleophilic moieties of the dinucleophilic monomer to react withepoxy moieties to form a polymer backbone containing pendant hydroxymoieties and ether, imino, amino, sulfonamido or ester linkages. Thesehydroxy-phenoxyether polymers are described in U.S. Pat. No. 5,184,373.

The poly(hydroxyamino ethers) (“PHAE” or polyetheramines) represented byFormula VIII are prepared by contacting one or more of the diglycidylethers of a dihydric phenol with an amine having two amine hydrogensunder conditions sufficient to cause the amine moieties to react withepoxy moieties to form a polymer backbone having amine linkages, etherlinkages and pendant hydroxyl moieties. These compounds are described inU.S. Pat. No. 5,275,853. For example, polyhydroxyaminoether copolymerscan be made from resorcinol diglycidyl ether, hydroquinone diglycidylether, bisphenol A diglycidyl ether, or mixtures thereof.

The hydroxy-phenoxyether polymers are the condensation reaction productsof a dihydric polynuclear phenol, such as bisphenol A, and anepihalohydrin and have the repeating units represented by Formula IVwherein Ar is an isopropylidene diphenylene moiety. The process forpreparing these is described in U.S. Pat. No. 3,305,528, incorporatedherein by reference in its entirety. One preferred non-limitinghydroxy-phenoxyether polymer, PAPHEN 25068-38-6, is commerciallyavailable from Phenoxy Associates, Inc. Other preferred phenoxy resinsare available from InChem® (Rock Hill, S.C.), these materials include,but are not limited to, the INCHEMREZ™ PKHH and PKHW product lines.

Generally, preferred phenoxy-type materials form stable aqueous basedsolutions or dispersions. Preferably, the properties of thesolutions/dispersions are not adversely affected by contact with water.Preferred materials range from about 10% solids to about 50% solids,including about 15%, 20%, 25%, 30%, 35%, 40% and 45%, and rangesencompassing such percentages. Preferably, the material used dissolvesor disperses in polar solvents. These polar solvents include, but arenot limited to, water, alcohols, and glycol ethers. See, for example,U.S. Pat. Nos. 6,455,116, 6,180,715, and 5,834,078 which describe somepreferred phenoxy-type solutions and/or dispersions.

One preferred phenoxy-type material is a polyhydroxyaminoether copolymer(PHAE), represented by Formula VIII, dispersion or solution. Thedispersion or solution, when applied to a container or preform, greatlyreduces the permeation rate of a variety of gases through the containerwalls in a predictable and well known manner. One dispersion or latexmade thereof comprises 10-30 percent solids. A PHAE solution/dispersionmay be prepared by stirring or otherwise agitating the PHAE in asolution of water with an organic acid, preferably acetic or phosphoricacid, but also including lactic, malic, citric, or glycolic acid and/ormixtures thereof. These PHAE solution/dispersions also include organicacid salts produced by the reaction of the polyhydroxyaminoethers withthese acids.

In other preferred embodiments, phenoxy-type thermoplastics are mixed orblended with other materials using methods known to those of skill inthe art. In some embodiments a compatibilizer may be added to the blend.When compatibilizers are used, preferably one or more properties of theblends are improved, such properties including, but not limited to,color, haze, and adhesion between a layer comprising a blend and otherlayers. One preferred blend comprises one or more phenoxy-typethermoplastics and one or more polyolefins. A preferred polyolefincomprises polypropylene. In one embodiment polypropylene or otherpolyolefins may be grafted or modified with a polar molecule or monomer,including, but not limited to, maleic anhydride, glycidyl methacrylate,acryl methacrylate and/or similar compounds to increase compatibility.

The following PHAE solutions or dispersions are examples of suitablephenoxy-type solutions or dispersions which may be used if one or morelayers of resin are applied as a liquid such as by dip, flow, or spraycoating, such as described in WO 04/004929 and U.S. Pat. No. 6,676,883.One suitable material is BLOX® experimental barrier resin, for exampleXU-19061.00 made with phosphoric acid manufactured by Dow ChemicalCorporation. This particular PHAE dispersion is said to have thefollowing typical characteristics: 30% percent solids, a specificgravity of 1.30, a pH of 4, a viscosity of 24 centipoise (Brookfield, 60rpm, LVI, 22° C.), and a particle size of between 1,400 and 1,800angstroms. Other suitable materials include BLOX® 588-29 resins based onresorcinol have also provided superior results as a barrier material.This particular dispersion is said to have the following typicalcharacteristics: 30% percent solids, a specific gravity of 1.2, a pH of4.0, a viscosity of 20 centipoise (Brookfield, 60 rpm, LVI, 22° C.), anda particle size of between 1500 and 2000 angstroms. Other variations ofthe polyhydroxyaminoether chemistry may prove useful such as crystallineversions based on hydroquinone diglycidylethers. Other suitablematerials include polyhydroxyaminoether solutions/dispersions byImperial Chemical Industries (“ICI,” Ohio, USA) available under the nameOXYBLOK. In one embodiment, PHAE solutions or dispersions can becrosslinked partially (semi-cross linked), fully, or to the exactdesired degree as appropriate for the application by adding anappropriate cross linker material. The benefits of cross linkinginclude, but are not limited to, one or more of the following: improvedchemical resistance, improved abrasion resistance, low blushing, lowsurface tension. Examples of cross linker materials include, but are notlimited to, formaldehyde, acetaldehyde or other members of the aldehydefamily of materials. Suitable cross linkers can also enable changes tothe T_(g) of the material, which can facilitate formation of specificcontainers. Other suitable materials include BLOX® 5000 resin dispersionintermediate, BLOX® XUR 588-29, BLOX® 0000 and 4000 series resins. Thesolvents used to dissolve these materials include, but are not limitedto, polar solvents such as alcohols, water, glycol ethers or blendsthereof. Other suitable materials include, but are not limited to, BLOX®R1.

In one embodiment, preferred phenoxy-type thermoplastics are soluble inaqueous acid. A polymer solution/dispersion may be prepared by stirringor otherwise agitating the thermoplastic epoxy in a solution of waterwith an organic acid, preferably acetic or phosphoric acid, but alsoincluding lactic, malic, citric, or glycolic acid and/or mixturesthereof. In a preferred embodiment, the acid concentration in thepolymer solution is preferably in the range of about 5%-20%, includingabout 5%-10% by weight based on total weight. In other preferredembodiments, the acid concentration may be below about 5% or above about20%; and may vary depending on factors such as the type of polymer andits molecular weight. In other preferred embodiments, the acidconcentration ranges from about 2.5 to about 5% by weight. The amount ofdissolved polymer in a preferred embodiment ranges from about 0.1% toabout 40%. A uniform and free flowing polymer solution is preferred. Inone embodiment a 10% polymer solution is prepared by dissolving thepolymer in a 10% acetic acid solution at 90° C. Then while still hot thesolution is diluted with 20% distilled water to give an 8% polymersolution. At higher concentrations of polymer, the polymer solutiontends to be more viscous.

Examples of preferred copolyester materials and a process for theirpreparation is described in U.S. Pat. No. 4,578,295 to Jabarin. They aregenerally prepared by heating a mixture of at least one reactantselected from isophthalic acid, terephthalic acid and their C_(1 to C) ₄alkyl esters with 1,3 bis(2-hydroxyethoxy)benzene and ethylene glycol.Optionally, the mixture may further comprise one or more ester-formingdihydroxy hydrocarbon and/or bis(4-β-hydroxyethoxyphenyl)sulfone.Especially preferred copolyester materials are available from MitsuiPetrochemical Ind. Ltd. (Japan) as B-010, B-030 and others of thisfamily.

Examples of preferred polyamide materials include MXD-6 from MitsubishiGas Chemical (Japan). Other preferred polyamide materials include Nylon6, and Nylon 66. Other preferred polyamide materials are blends ofpolyamide and polyester, including those comprising about 1-20%polyester by weight, more preferably about 1-10% polyester by weight,where the polyester is preferably PET or a modified PET. In anotherembodiment, preferred polyamide materials are blends of polyamide andpolyester, including those comprising about 1-20% polyamide by weight,more preferably about 1-10% polyamide by weight, where the polyester ispreferably PET or a modified PET. The blends may be ordinary blends orthey may be compatibilized with an antioxidant or other material.Examples of such materials include those described in U.S. PatentPublication No. 2004/0013833, filed Mar. 21, 2003, which is herebyincorporated by reference in its entirety. Other preferred polyestersinclude, but are not limited to, PEN and PET/PEN copolymers.

3. Preferred Foam Materials

As used herein, the term “foam material” is a broad term and is used inaccordance with its ordinary meaning and may include, withoutlimitation, a foaming agent, a mixture of foaming agent and a binder orcarrier material, an expandable cellular material, and/or a materialhaving voids. The terms “foam material” and “expandable material” areused interchangeably herein. Preferred foam materials may exhibit one ormore physical characteristics that improve the thermal and/or structuralcharacteristics of articles (e.g., containers) and may enable thepreferred embodiments to be able to withstand processing and physicalstresses typically experienced by containers. In one embodiment, thefoam material provides structural support to the container. In anotherembodiment, the foam material forms a protective layer that can reducedamage to the container during processing. For example, the foammaterial can provide abrasion resistance which can reduce damage to thecontainer during transport. In one embodiment, a protective layer offoam may increase the shock or impact resistance of the container andthus prevent or reduce breakage of the container. Furthermore, inanother embodiment foam can provide a comfortable gripping surfaceand/or enhance the aesthetics or appeal of the container.

In one embodiment, foam material comprises a foaming or blowing agentand a carrier material. In one preferred embodiment, the foaming agentcomprises expandable structures (e.g., microspheres) that can beexpanded and cooperate with the carrier material to produce foam. Forexample, the foaming agent can be thermoplastic microspheres, such asEXPANCEL® microspheres sold by Akzo Nobel. In one embodiment,microspheres can be thermoplastic hollow spheres comprisingthermoplastic shells that encapsulate gas. Preferably, when themicrospheres are heated, the thermoplastic shell softens and the gasincreases its pressure causing the expansion of the microspheres from aninitial position to an expanded position. The expanded microspheres andat least a portion of the carrier material can form the foam portion ofthe articles described herein. The foam material can form a layer thatcomprises a single material (e.g., a generally homogenous mixture of thefoaming agent and the carrier material), a mix or blend of materials, amatrix formed of two or more materials, two or more layers, or aplurality of microlayers (lamellae) preferably including at least twodifferent materials. Alternatively, the microspheres can be any othersuitable controllably expandable material. For example, the microspherescan be structures comprising materials that can produce gas within orfrom the structures. In one embodiment, the microspheres are hollowstructures containing chemicals which produce or contain gas wherein anincrease in gas pressure causes the structures to expand and/or burst.In another embodiment, the microspheres are structures made from and/orcontaining one or more materials which decompose or react to produce gasthereby expanding and/or bursting the microspheres. Optionally, themicrosphere may be generally solid structures. Optionally, themicrospheres can be shells filled with solids, liquids, and/or gases.The microspheres can have any configuration and shape suitable forforming foam. For example, the microspheres can be generally spherical.Optionally, the microspheres can be elongated or oblique spheroids.Optionally, the microspheres can comprise any gas or blends of gasessuitable for expanding the microspheres. In one embodiment, the gas cancomprise an inert gas, such as nitrogen. In one embodiment, the gas isgenerally non-flammable. However, in certain embodiments non-inert gasand/or flammable gas can fill the shells of the microspheres. In someembodiments, the foam material may comprise foaming or blowing agents asare known in the art. Additionally, the foam material may be mostly orentirely foaming agent.

Although some preferred embodiments contain microspheres that generallydo not break or burst, other embodiments comprise microspheres that maybreak, burst, fracture, and/or the like. Optionally, a portion of themicrospheres may break while the remaining portion of the microspheresdoes not break. In some embodiments up to about 0.5%, 1%, 2%, 3%, 4%,5%, 10%, 20%, 30%, 40%, 50%, 60% 70%, 80%, 90% by weight ofmicrospheres, and ranges encompassing these amounts, break. In oneembodiment, for example, a substantial portion of the microspheres mayburst and/or fracture when they are expanded. Additionally, variousblends and mixtures of microspheres can be used to form foam material.

The microspheres can be formed of any material suitable for causingexpansion. In one embodiment, the microspheres can have a shellcomprising a polymer, resin, thermoplastic, thermoset, or the like asdescribed herein. The microsphere shell may comprise a single materialor a blend of two or more different materials. For example, themicrospheres can have an outer shell comprising ethylene vinyl acetate(“EVA”), polyethylene terephthalate (“PET”), polyamides (e.g. Nylon 6and Nylon 66) polyethylene terephthalate glycol (PETG), PEN, PETcopolymers, and combinations thereof. In one embodiment a PET copolymercomprises CHDM comonomer at a level between what is commonly called PETGand PET. In another embodiment, comonomers such as DEG and IPA are addedto PET to form miscrosphere shells. The appropriate combination ofmaterial type, size, and inner gas can be selected to achieve thedesired expansion of the microspheres. In one embodiment, themicrospheres comprise shells formed of a high temperature material(e.g., PETG or similar material) that is capable of expanding whensubject to high temperatures, preferably without causing themicrospheres to burst. If the microspheres have a shell made of lowtemperature material (e.g., as EVA), the microspheres may break whensubjected to high temperatures that are suitable for processing certaincarrier materials (e.g., PET or polypropylene having a high melt point).In some circumstances, for example, EXPANCEL® microspheres may be breakwhen processed at relatively high temperatures. Advantageously, mid orhigh temperature microspheres can be used with a carrier material havinga relatively high melt point to produce controllably, expandable foammaterial without breaking the microspheres. For example, microspherescan comprise a mid temperature material (e.g., PETG) or a hightemperature material (e.g., acrylonitrile) and may be suitable forrelatively high temperature applications. Thus, a blowing agent forfoaming polymers can be selected based on the processing temperaturesemployed.

The foam material can be a matrix comprising a carrier material,preferably a material that can be mixed with a blowing agent (e.g.,microspheres) to form an expandable material. The carrier material canbe a thermoplastic, thermoset, or polymeric material, such as ethyleneacrylic acid (“EAA”), ethylene vinyl acetate (“EVA”), linear low densitypolyethylene (“LLDPE”), polyethylene terephthalate glycol (PETG),poly(hydroxyamino ethers) (“PHAE”), PET, polyethylene, polypropylene,polystyrene (“PS”), pulp (e.g., wood or paper pulp of fibers, or pulpmixed with one or more polymers), mixtures thereof, and the like.However, other materials suitable for carrying the foaming agent can beused to achieve one or more of the desired thermal, structural, optical,and/or other characteristics of the foam. In some embodiments, thecarrier material has properties (e.g., a high melt index) for easier andrapid expansion of the microspheres, thus reducing cycle time therebyresulting in increased production.

In preferred embodiments, the formable material may comprise two or morecomponents including a plurality of components each having differentprocessing windows and/or physical properties. The components can becombined such that the formable material has one or more desiredcharacteristics. The proportion of components can be varied to produce adesired processing window and/or physical properties. For example, thefirst material may have a processing window that is similar to ordifferent than the processing window of the second material. Theprocessing window may be based on, for example, pressure, temperature,viscosity, or the like. Thus, components of the formable material can bemixed to achieve a desired, for example, pressure or temperature rangefor shaping the material.

In one embodiment, the combination of a first material and a secondmaterial may result in a material having a processing window that ismore desirable than the processing window of the second material. Forexample, the first material may be suitable for processing over a widerange of temperatures, and the second material may be suitable forprocessing over a narrow range of temperatures. A material having aportion formed of the first material and another portion formed of thesecond material may be suitable for processing over a range oftemperatures that is wider than the narrow range of processingtemperatures of the second material. In one embodiment, the processingwindow of a multi-component material is similar to the processing windowof the first material. In one embodiment, the formable materialcomprises a multilayer sheet or tube comprising a layer comprising PETand a layer comprising polypropylene. The material formed from both PETand polypropylene can be processed (e.g., extruded) within a widetemperature range similar to the processing temperature range suitablefor PET. The processing window may be for one or more parameters, suchas pressure, temperature, viscosity, and/or the like.

Optionally, the amount of each component of the material can be variedto achieve the desired processing window. Optionally, the materials canbe combined to produce a formable material suitable for processing overa desired range of pressure, temperature, viscosity, and/or the like.For example, the proportion of the material having a more desirableprocessing window can be increased and the proportion of material havinga less undesirable processing window can be decreased to result in amaterial having a processing window that is very similar to or issubstantially the same as the processing window of the first material.Of course, if the more desired processing window is between a firstprocessing window of a first material and the second processing windowof a second material, the proportion of the first and the secondmaterial can be chosen to achieve a desired processing window of theformable material.

Optionally, a plurality of materials each having similar or differentprocessing windows can be combined to obtain a desired processing windowfor the resultant material.

In one embodiment, the Theological characteristics of a formablematerial can be altered by varying one or more of its components havingdifferent Theological characteristics. For example, a substrate (e.g.,PP) may have a high melt strength and is amenable to extrusion. PP canbe combined with another material, such as PET which has a low meltstrength making it difficult to extrude, to form a material suitable forextrusion processes. For example, a layer of PP or other strong materialmay support a layer of PET during co-extrusion (e.g., horizontal orvertical co-extrusion). Thus, formable material formed of PET andpolypropylene can be processed, e.g., extruded, in a temperature rangegenerally suitable for PP and not generally suitable for PET.

In some embodiments, the composition of the formable material may beselected to affect one or more properties of the articles. For example,the thermal properties, structural properties, barrier properties,optical properties, rheology properties, favorable flavor properties,and/or other properties or characteristics disclosed herein can beobtained by using formable materials described herein.

4. Additives to Enhance Materials

An advantage of preferred methods disclosed herein are their flexibilityallowing for the use of multiple functional additives. Additives knownby those of ordinary skill in the art for their ability to provideenhanced CO₂ barriers, O₂ barriers, UV protection, scuff resistance,blush resistance, impact resistance and/or chemical resistance may beused.

Preferred additives may be prepared by methods known to those of skillin the art. For example, the additives may be mixed directly with aparticular material, they may be dissolved/dispersed separately and thenadded to a particular material, or they may be combined with aparticular material to addition of the solvent that forms the materialsolution/dispersion. In addition, in some embodiments, preferredadditives may be used alone as a single layer.

In preferred embodiments, the barrier properties of a layer may beenhanced by the addition of different additives. Additives arepreferably present in an amount up to about 40% of the material, alsoincluding up to about 30%, 20%, 10%, 5%, 2% and 1% by weight of thematerial. In other embodiments, additives are preferably present in anamount less than or equal to 1% by weight, preferred ranges of materialsinclude, but are not limited to, about 0.01% to about 1%, about 0.01% toabout 0.1%, and about 0.1% to about 1% by weight. Further, in someembodiments additives are preferably stable in aqueous conditions. Forexample, derivatives of resorcinol (m-dihydroxybenzene) may be used inconjunction with various preferred materials as blends or as additivesor monomers in the formation of the material. The higher the resorcinolcontent the greater the barrier properties of the material. For example,resorcinol diglycidyl ether can be used in PHAE and hydroxyethyl etherresorcinol can be used in PET and other polyesters and CopolyesterBarrier Materials.

Another additive(s) that may be used are “nanoparticles” or“nanoparticulate material.” For convenience the term nanoparticles willbe used herein to refer to both nanoparticles and nanoparticulatematerial. These nanoparticles are tiny, micron or sub-micron size(diameter), particles of materials which enhance the barrier propertiesof a material by creating a more tortuous path for migrating gasmolecules, e.g. oxygen or carbon dioxide, to take as they permeate amaterial. In preferred embodiments nanoparticulate material is presentin amounts ranging from 0.05 to 1% by weight, including 0.1%, 0.5% byweight and ranges encompassing these amounts.

One preferred type of nanoparticulate material is a microparticular claybased product available from Southern Clay Products. One preferred lineof products available from Southern Clay products is Cloisite®nanoparticles. In one embodiment preferred nanoparticles comprisemonmorillonite modified with a quaternary ammonium salt. In otherembodiments nanoparticles comprise monmorillonite modified with aternary ammonium salt. In other embodiments nanoparticles comprisenatural monmorillonite. In further embodiments, nanoparticles compriseorganoclays as described in U.S. Pat. No. 5,780,376, the entiredisclosure of which is hereby incorporated by reference and forms partof the disclosure of this application. Other suitable organic andinorganic microparticular clay based products may also be used. Bothman-made and natural products are also suitable.

Another type of preferred nanoparticulate material comprises a compositematerial of a metal. For example, one suitable composite is a waterbased dispersion of aluminum oxide in nanoparticulate form availablefrom BYK Chemie (Germany). It is believed that this type ofnanoparticular material may provide one or more of the followingadvantages: increased abrasion resistance, increased scratch resistance,increased T_(g), and thermal stability.

Another type of preferred nanoparticulate material comprises apolymer-silicate composite. In preferred embodiments the silicatecomprises montmorillonite. Suitable polymer-silicate nanoparticulatematerial are available from Nanocor and RTP Company.

In preferred embodiments, the UV protection properties of the materialmay be enhanced by the addition of different additives. In a preferredembodiment, the UV protection material used provides UV protection up toabout 350 nm or less, preferably about 370 nm or less, more preferablyabout 400 nm or less. The UV protection material may be used as anadditive with layers providing additional functionality or appliedseparately as a single layer. Preferably additives providing enhanced UVprotection are present in the material from about 0.05 to 20% by weight,but also including about 0.1%, 0.5%, 1%, 2%, 3%, 5%, 10%, and 15% byweight, and ranges encompassing these amounts. Preferably the UVprotection material is added in a form that is compatible with the othermaterials. For example, a preferred UV protection material is MillikenUV390A ClearShield®. UV390A is an oily liquid for which mixing is aidedby first blending the liquid with water, preferably in roughly equalparts by volume. This blend is then added to the material solution, forexample, BLOX® 599-29, and agitated. The resulting solution containsabout 10% UV390A and provides UV protection up to 390 nm when applied toa PET preform. As previously described, in another embodiment the UV390Asolution is applied as a single layer. In other embodiments, a preferredUV protection material comprises a polymer grafted or modified with a UVabsorber that is added as a concentrate. Other preferred UV protectionmaterials include, but are not limited to, benzotriazoles,phenothiazines, and azaphenothiazines. UV protection materials may beadded during the melt phase process prior to use, e.g. prior toinjection molding or extrusion, or added directly to a coating materialthat is in the form of a solution or dispersion. Suitable UV protectionmaterials are available from Milliken, Ciba and Clariant.

In preferred embodiments, CO₂ scavenging properties can be added to thematerials. In one preferred embodiment such properties are achieved byincluding an active amine which will react with CO₂ forming a high gasbarrier salt. This salt will then act as a passive CO₂ barrier. Theactive amine may be an additive or it may be one or more moieties in thethermoplastic resin material of one or more layers.

In preferred embodiments, O₂ scavenging properties can be added topreferred materials by including O₂ scavengers such as anthroquinone andothers known in the art. In another embodiment, one suitable O₂scavenger is AMOSORB® O₂ scavenger available from BP Amoco Corporationand ColorMatrix Corporation which is disclosed in U.S. Pat. No.6,083,585 to Cahill et al., the disclosure of which is herebyincorporated in its entirety. In one embodiment, O₂ scavengingproperties are added to preferred phenoxy-type materials, or othermaterials, by including O₂ scavengers in the phenoxy-type material, withdifferent activating mechanisms. Preferred O₂ scavengers can act eitherspontaneously, gradually or with delayed action until initiated by aspecific trigger. In some embodiments the O₂ scavengers are activatedvia exposure to either UV or water (e.g., present in the contents of thecontainer), or a combination of both. The O₂ scavenger is preferablypresent in an amount of from about 0.1 to about 20 percent by weight,more preferably in an amount of from about 0.5 to about 10 percent byweight, and, most preferably, in an amount of from about 1 to about 5percent by weight, based on the total weight of the coating layer.

In another preferred embodiment, a top coat or layer is applied toprovide chemical resistance to harsher chemicals than what is providedby the outer layer. In certain embodiments, preferably these top coatsor layers are aqueous based or non-aqueous based polyesters or acrylicswhich are optionally partially or fully cross linked. A preferredaqueous based polyester is polyethylene terephthalate, however otherpolyesters may also be used. In certain embodiments, the process ofapplying the top coat or layer is that disclosed in U.S. Patent Pub. No.2004/0071885, entitled Dip, Spray, and Flow Coating Process For FormingCoated Articles, the entire disclosure of which is hereby incorporatedby reference in its entirety.

A preferred aqueous based polyester resin is described in U.S. Pat. No.4,977,191 (Salsman), incorporated herein by reference. Morespecifically, U.S. Pat. No. 4,977,191 describes an aqueous basedpolyester resin, comprising a reaction product of 20-50% by weight ofwaste terephthalate polymer, 10-40% by weight of at least one glycol an5-25% by weight of at least one oxyalkylated polyol.

Another preferred aqueous based polymer is a sulfonated aqueous basedpolyester resin composition as described in U.S. Pat. No. 5,281,630(Salsman), herein incorporated by reference. Specifically, U.S. Pat. No.5,281,630 describes an aqueous suspension of a sulfonated water-solubleor water dispersible polyester resin comprising a reaction product of20-50% by weight terephthalate polymer, 10-40% by weight at least oneglycol and 5-25% by weight of at least one oxyalkylated polyol toproduce a prepolymer resin having hydroxyalkyl functionality where theprepolymer resin is further reacted with about 0.10 mole to about 0.50mole of alpha, beta-ethylenically unsaturated dicarboxylic acid per 100g of prepolymer resin and a thus produced resin, terminated by a residueof an alpha, beta-ethylenically unsaturated dicarboxylic acid, isreacted with about 0.5 mole to about 1.5 mole of a sulfite per mole ofalpha, beta-ethylenically unsaturated dicarboxylic acid residue toproduce a sulfonated-terminated resin.

Yet another preferred aqueous based polymer is the coating described inU.S. Pat. No. 5,726,277 (Salsman), incorporated herein by reference.Specifically, U.S. Pat. No. 5,726,277 describes coating compositionscomprising a reaction product of at least 50% by weight of wasteterephthalate polymer and a mixture of glycols including an oxyalkylatedpolyol in the presence of a glycolysis catalyst wherein the reactionproduct is further reacted with a difunctional, organic acid and whereinthe weight ratio of acid to glycols in is the range of 6:1 to 1:2.

While the above examples are provided as preferred aqueous based polymercoating compositions, other aqueous based polymers are suitable for usein the products and methods describe herein. By way of example only, andnot meant to be limiting, further suitable aqueous based compositionsare described in U.S. Pat. No. 4,104,222 (Date, et al.), incorporatedherein by reference. U.S. Pat. No. 4,104,222 describes a dispersion of alinear polyester resin obtained by mixing a linear polyester resin witha higher alcohol/ethylene oxide addition type surface-active agent,melting the mixture and dispersing the resulting melt by pouring it intoan aqueous solution of an alkali under stirring Specifically, thisdispersion is obtained by mixing a linear polyester resin with asurface-active agent of the higher alcohol/ethylene oxide addition type,melting the mixture, and dispersing the resulting melt by pouring itinto an aqueous solution of an alkanolamine under stirring at atemperature of 70-95° C., said alkanolamine being selected from thegroup consisting of monoethanolamine, diethanolamine, triethanolamine,monomethylethanolamine, monoethylethanolamine, diethylethanolamine,propanolamine, butanolamine, pentanolamine, N-phenylethanolamine, and analkanolamine of glycerin, said alkanolamine being present in the aqueoussolution in an amount of 0.2 to 5 weight percent, said surface-activeagent of the higher alcohol/ethylene oxide addition type being anethylene oxide addition product of a higher alcohol having an alkylgroup of at least 8 carbon atoms, an alkyl-substituted phenol or asorbitan monoacylate and wherein said surface-active agent has an HLBvalue of at least 12.

Likewise, by example, U.S. Pat. No. 4,528,321 (Allen) discloses adispersion in a water immiscible liquid of water soluble or waterswellable polymer particles and which has been made by reverse phasepolymerization in the water immiscible liquid and which includes anon-ionic compound selected from C₄₋₁₂ alkylene glycol monoethers, theirC₁₋₄ alkanoates, C₆₋₁₂ polyakylene glycol monoethers and their C₁₋₄alkanoates.

The materials of certain embodiments may be cross-linked to enhancethermal stability for various applications, for example hot fillapplications. In one embodiment, inner layers may comprise low-crosslinking materials while outer layers may comprise high crosslinkingmaterials or other suitable combinations. For example, an inner coatingon a PET surface may utilize non or low cross-linked material, such asthe BLOX® 588-29, and the outer coat may utilize another material, suchas EXP 12468-4b from ICI, capable of cross linking to ensure maximumadhesion to the PET. Suitable additives capable of cross linking may beadded to one or more layers. Suitable cross linkers can be chosendepending upon the chemistry and functionality of the resin or materialto which they are added. For example, amine cross linkers may be usefulfor crosslinking resins comprising epoxide groups. Preferably crosslinking additives, if present, are present in an amount of about 1% to10% by weight of the coating solution/dispersion, preferably about 1% to5%, more preferably about 0.01% to 0.1% by weight, also including 2%,3%, 4%, 6%, 7%, 8%, and 9% by weight. Optionally, a thermoplastic epoxy(TPE) can be used with one or more crosslinking agents. In someembodiments, agents (e.g. carbon black) may also be coated onto orincorporated into the TPE material. The TPE material can form part ofthe articles disclosed herein. It is contemplated that carbon black orsimilar additives can be employed in other polymers to enhance materialproperties.

The materials of certain embodiments may optionally comprise a curingenhancer. As used herein, the term “curing enhancer” is a broad term andis used in its ordinary meaning and includes, without limitation,chemical cross-linking catalyst, thermal enhancer, and the like. As usedherein, the term “thermal enhancer” is a broad term and is used in itsordinary meaning and includes, without limitation, transition metals,transition metal compounds, radiation absorbing additives (e.g., carbonblack). Suitable transition metals include, but are not limited to,cobalt, rhodium, and copper. Suitable transition metal compoundsinclude, but are not limited to, metal carboxylates. Preferredcarboxylates include, but are not limited to, neodecanoate, octoate, andacetate. Thermal enhancers may be used alone or in combination with oneor more other thermal enhancers.

The thermal enhancer can be added to a material and may significantlyincrease the temperature of the material during a curing process, ascompared to the material without the thermal enhancer. For example, insome embodiments, the thermal enhancer (e.g., carbon black) can be addedto a polymer so that the temperature of the polymer subjected to acuring process (e.g., IR radiation) is significantly greater than thepolymer without the thermal enhancer subject to the same or similarcuring process. The increased temperature of the polymer caused by thethermal enhancer can increase the rate of curing and therefore increaseproduction rates. In some embodiments, the thermal enhancer generallyhas a higher temperature than at least one of the layers of an articlewhen the thermal enhancer and the article are heated with a heatingdevice (e.g., infrared heating device).

In some embodiments, the thermal enhancer is present in an amount ofabout 5 to 800 ppm, preferably about 20 to about 150 ppm, preferablyabout 50 to 125 ppm, preferably about 75 to 100 ppm, also includingabout 10, 20, 30, 40, 50, 75, 100, 125, 150, 175, 200, 300, 400, 500,600, and 700 ppm and ranges encompassing these amounts. The amount ofthermal enhancer may be calculated based on the weight of layer whichcomprises the thermal enhancer or the total weight of all layerscomprising the article.

In some embodiments, a preferred thermal enhancer comprises carbonblack. In one embodiment, carbon black can be applied as a component ofa coating material in order to enhance the curing of the coatingmaterial. When used as a component of a coating material, carbon blackis added to one or more of the coating materials before, during, and/orafter the coating material is applied (e.g., impregnated, coated, etc.)to the article. Preferably carbon black is added to the coating materialand agitated to ensure thorough mixing. The thermal enhancer maycomprise additional materials to achieve the desired material propertiesof the article.

In another embodiment wherein carbon black is used in an injectionmolding process, the carbon black may be added to the polymer blend inthe melt phase process.

In some embodiments, the polymer comprises about 5 to 800 ppm,preferably about 20 to about 150 ppm, preferably about 50 to 125 ppm,preferably about 75 to 100 ppm, also including about 10, 20, 30, 40, 50,75, 100, 125, 150, 175, 200, 300, 400, 500, 600, and 700 ppm thermalenhancer and ranges encompassing these amounts. In a further embodiment,the coating material is cured using radiation, such as infrared (IR)heating. In preferred embodiments, the IR heating provides a moreeffective coating than curing using other methods. Other thermal andcuring enhancers and methods of using same are disclosed in U.S. patentapplication Ser. No. 10/983,150, filed Nov. 5, 2004, entitled “CatalyzedProcess for Forming Coated Articles,” the disclosure of which is herebyincorporated by reference it its entirety.

In some embodiments the addition of anti-foam/bubble agents isdesirable. In some embodiments utilizing solutions or dispersion thesolutions or dispersions form foam and/or bubbles which can interferewith preferred processes. One way to avoid this interference, is to addanti-foam/bubble agents to the solution/dispersion. Suitable anti-foamagents include, but are not limited to, nonionic surfactants, alkyleneoxide based materials, siloxane based materials, and ionic surfactants.Preferably anti-foam agents, if present, are present in an amount ofabout 0.01% to about 0.3% of the solution/dispersion, preferably about0.01% to about 0.2%, but also including about 0.02%, 0.03%, 0.04%,0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.25%, and ranges encompassingthese amounts.

In another embodiment foaming agents may be added to the coatingmaterials in order to foam the coating layer. In a further embodiment areaction product of a foaming agent is used. Useful foaming agentsinclude, but are not limited to azobisformamide, azobisisobutyronitrile,diazoaminobenzene, N,N-dimethyl-N,N-dinitroso terephthalamide,N,N-dinitrosopentamethylene-tetramine, benzenesulfonyl-hydrazide,benzene-1,3-disulfonyl hydrazide, diphenylsulfon-3-3, disulfonylhydrazide, 4,4′-oxybis benzene sulfonyl hydrazide, p-toluene sulfonylsemicarbizide, barium azodicarboxylate, butylamine nitrile, nitroureas,trihydrazino triazine, phenyl-methyl-urethane, p-sulfonhydrazide,peroxides, ammonium bicarbonate, and sodium bicarbonate. As presentlycontemplated, commercially available foaming agents include, but are notlimited to, EXPANCEL®, CELOGEN®, HYDROCEROL®, MIKROFINE®, CEL-SPAN®, andPLASTRON® FOAM.

The foaming agent is preferably present in the coating material in anamount from about 1 up to about 20 percent by weight, more preferablyfrom about 1 to about 10 percent by weight, and, most preferably, fromabout 1 to about 5 percent by weight, based on the weight of the coatinglayer. Newer foaming technologies known to those of skill in the artusing compressed gas could also be used as an alternate means togenerate foam in place of conventional blowing agents listed above.

The tie-layer is preferably a polymer having functional groups, such asanhydrides and epoxies that react with the carboxyl and/or hydroxylgroups on the PET polymer chains. Useful tie-layer materials include,but are not limited to, DuPont BYNEL®, Mitsui ADMER®, Eastman's EPOLINE,Arkema's LOTADER and ExxonMobil's EVELOY®.

B. Detailed Description of the Drawings

In preferred embodiments articles may comprise one or more formablematerials. Articles described herein may be mono-layer or multi-layer(i.e., two or more layers). In some embodiments, the articles can bepackaging, such as drinkware (including preforms, containers, bottles,closures, etc.), boxes, cartons, tray, sheets, and the like.

The multi-layer articles may comprise an inner layer (e.g., the layerthat is in contact with the contents of the container) of a materialapproved by a regulatory agency (e.g., the U.S. Food and DrugAssociation) or material having regulatory approval to be in contactwith food (including beverages), drugs, cosmetics, etc. In otherembodiments, an inner layer comprises material(s) that are not approvedby a regulatory scheme to be in contact with food. A second layer maycomprise a second material, which can be similar to or different thanthe material forming the inner layer. The articles can have as manylayers as desired. It is contemplated that the articles may comprise oneor more materials that form various portions that are not “layers.”

Referring to FIG. 1, a preferred monolayer preform 30 is illustrated.The preform is preferably made of an FDA approved material, such asvirgin PET, and can be of any of a wide variety of shapes and sizes. Thepreform shown in FIG. 1 is of the type which will form a 16 oz.carbonated beverage bottle that can have an oxygen and carbon dioxidebarrier, but as will be understood by those skilled in the art, otherpreform configurations can be used depending upon the desiredconfiguration, characteristics and use of the final article. Themonolayer preform 30 may be made by methods disclosed herein.

Referring to FIG. 2, a cross-section of the preform 30 of FIG. 1 isillustrated. The preform 30 has a neck portion 32 and a body portion 34,formed monolithically (i.e., as a single, or unitary, structure).Advantageously, the monolithic arrangement of the preform, whenblow-molded into a bottle, provides greater dimensional stability andimproved physical properties in comparison to a preform constructed ofseparate neck and body portions, which are bonded together. However, thepreforms can comprise a neck portion and body portion that are bondedtogether.

The neck portion 32 begins at the opening 36 to the interior of thepreform 30 and extends to and includes the support ring 38. The neckportion 32 is further characterized by the presence of the threads 40,which provide a way to fasten a cap for the bottle produced from thepreform 30. Alternatively, the neck portion 32 can be configured toengage a closure or cap (e.g., a crown closure, cork (natural orartificial), snap cap, punctured seal, and/or the like). The bodyportion 34 is an elongated and cylindrically shaped structure extendingdown from the neck portion 32 and culminating in a rounded end cap 42.The preform thickness 44 will depend upon the overall length of thepreform 30 and the wall thickness and overall size of the resultingcontainer.

Referring to FIG. 3, a cross-section of one type of a multilayer preform50 having features in accordance with a preferred embodiment isdisclosed. The preform 50 has the neck portion 32 and the body portion34 similar to the preform 30 in FIGS. 1 and 2. The layer 52 is disposedabout the entire surface of the body portion 34, terminating at thebottom of the support ring 38. The coating layer 52 in the embodimentshown in the figure does not extend to the neck portion 32, nor is itpresent on the interior surface 54 of the preform which is preferablymade of an FDA approved material, such as PET. The coating layer 52 maycomprise either a single material or several microlayers of at least twomaterials. By way of example, the wall of the bottom portion of thepreform may have a thickness of 3.2 millimeters; the wall of the neck, across-sectional dimension of about 3 millimeters; and the materialapplied to a thickness of about 0.3 millimeters. The layer 52 maycomprise PET, RPET, barrier material, foam and/or other polymermaterials suitable for forming an outer surface of a preform.

The overall thickness 56 of the preform is equal to the thickness of theinitial uncoated preform 39 plus the thickness 58 of the outer layer 52,and is dependent upon the overall size and desired coating thickness ofthe resulting container. However, the preform 50 may have any thicknessdepending on the desired thermal, or structural properties of thecontainer formed from the preform 50. The preforms and containers canhave layers which have a wide variety of relative thicknesses.

Referring to FIG. 4, a preferred embodiment of a multilayer preform 60is shown in cross-section. The primary difference between the coatedpreform 60 and the coated preform 50 in FIG. 3 is the relative thicknessof the two layers in the area of the end cap 42. The preform 50 of FIG.3 has an outer layer 52 that is generally thinner than the thickness ofthe inner layer of the preform throughout the entire body portion of thepreform. The preform 60, however, has an outer layer 52 that is thickerat 62 near the end cap 42 than it is at 64 in the wall portion 66, andconversely, the thickness of the inner layer is greater at 68 in thewall portion 66 than it is at 70, in the region of the end cap 42. Thispreform design is especially useful when the outer layer which isapplied to the initial preform in an overmolding process to make thecoated preform, as described below, where it presents certain advantagesincluding that relating to reducing molding cycle time. These advantageswill be discussed in more detail below. The layer 52 may be homogeneousor it may comprise a plurality of microlayers.

The multilayer preforms and containers can have layers which have a widevariety of relative thicknesses. In view of the present disclosure thethickness of a given layer and of the overall preform or container,whether at a given point or over the entire container, can be chosen tofit a coating process or a particular end use for the container.Furthermore, as discussed above in regard to the outer layer in FIG. 3,the outer layer in the preform and container embodiments disclosedherein may comprise a single material or several microlayers of two ormore materials.

Referring to FIG. 5 there is shown a preferred three-layer preform 72.This embodiment of coated preform is preferably made by placing twocoating layers 74 and 76 on a monolayer preform, such as preform 30shown in FIG. 1.

After a preform, such as that illustrated in FIG. 3, is prepared by amethod and apparatus such as those discussed in detail below, it issubjected to a stretch blow-molding process. Referring to FIG. 6, inthis process a multilayer preform 50 is placed in a mold 80 having acavity corresponding to the desired container shape. The preform is thenheated and expanded by stretching and by air forced into the interior ofthe preform 50 to fill the cavity within the mold 80, creating acontainer 82 (FIG. 7). The blow molding operation normally is restrictedto the body portion 34 of the preform with the neck portion 32 includingthe threads, pilfer ring, and support ring retaining the originalconfiguration as in the preform. Monolayer and multilayer containers canbe formed by stretch blow molding monolayer and multilayer preforms,respectively.

FIG. 6A illustrates a stretch blow mold designed to improve cycle timesand thermal efficiency. The temperature of the walls of the mold 80A canbe precisely controlled to achieve the desired temperature distributionthrough the blow molded container.

Referring to FIG. 7, there is disclosed an embodiment of container 82 inaccordance with a preferred embodiment, such as that which might be madefrom blow molding the multilayer preform 50 of FIG. 3. The container 82has a neck portion 32 and a body portion 34 corresponding to the neckand body portions of the preform 50 of FIG. 3. The neck portion 32 isfurther characterized by the presence of the threads 40 which provide away to fasten a cap onto the container.

The outer layer 84 covers the exterior of the entire body portion 34 ofthe container 82, stopping just below the support ring 38. The interiorsurface 86 of the container, which is made of an FDA-approved material,preferably PET, remains uncoated so that only the interior surface 86 isin contact with beverages or foodstuffs. In one preferred embodimentthat is used as a carbonated beverage container, the thickness 87 of thelayer is preferably 0.508 mm-1.524 mm (0.020-0.060 inch), morepreferably 0.762 mm-1.016 mm (0.030-0.040 inch); the thickness 88 of thePET layer is preferably 2.032 mm-4.064 mm (0.080-0.160 inch), morepreferably 2.54 mm-3.556 mm (0.100-0.140 inch); and the overall wallthickness 90 of the barrier-coated container 82 is preferably 3.556mm-4,562 mm (0.140-0.180 inch), more preferably 3.82 mm-4.318 mm(0.150-0.170 inch). Preferably, on average, the overall wall thickness90 of the container 82 derives the majority of its thickness from theinner PET layer. Of course, the container 82 can be a monolayercontainer. For example, the container 82 can be made by stretch blowmolding the preform 30 of FIG. 1. Additional articles and associatedmaterials are disclosed in U.S. patent application Ser. No. 11/108,345entitled MONO AND MULTI-LAYER ARTICLES AND INJECTION METHODS OF MAKINGTHE SAME, filed on Apr. 18, 2005 that can be made by the systemsdisclosed herein.

FIG. 8 schematically illustrates a temperature control system 120 inaccordance with a preferred embodiment. The illustrated temperaturecontrol system 120 is an open loop system. The temperature controlsystem 120 can be used to control the temperature of a mold apparatus122. The mold apparatus 122 can be configured to mold a single articleor a plurality of articles. The mold apparatus 122 can be configured toform articles of any shape and configuration. For example, the moldapparatus 122 can be designed to produce preforms, containers, and otherarticles that are formed by molds. In some embodiments, the moldapparatus 122 can be a stretch blow-molding apparatus, injection moldingapparatus, compression molding apparatus, thermomolding or thermoformingsystem, vacuum forming system, and the like. The mold apparatus 122 mayor may not comprise high heat transfer material. Some exemplarytemperature control systems employ a working fluid or other means forcontrolling the temperature of the mold apparatus during the moldingprocess. The illustrated temperature control system 120 has a workingfluid passing through the mold apparatus 122 to control the temperatureof the polymer in the mold apparatus 122. The working fluid can be at awide range of temperatures depending on the particular application.

The illustrated mold apparatus 122 comprises a plurality of moldsections that cooperate to define a molding cavity. In some embodiments,the mold apparatus 122 comprises a mold section 122 a and mold section122 b movable between an open position and a closed position. The moldsection 122 a and the mold section 122 b can form a mold cavity sizedand configured to make preforms, such as the preform 30 as illustrated.The mold apparatus 122 can also be designed to form a layer of amultilayer preforms or other articles. The temperature control system120 can be used selectively control the temperature of the moldapparatus 122 to reduce cycle time, produce a desired finish (e.g., anamount of crystallinity), improve mold life, improve preform quality,etc.

In the illustrated embodiment, the temperature control system 120includes fluid lines 130, 140. The fluid line 130 connects a fluidsource 126 to the mold apparatus 122, and the fluid line 140 connectsthe mold apparatus 122 to an exhaust system 148. Fluid lines can defineflow paths of the working fluid passing through the system 120.

As used herein, the term “fluid source” is a broad term and is used inits ordinary sense and refers, without limitation, to a device which issuitable for providing fluid that can be used to maintain the moldapparatus 122 at a suitable temperature. In various embodiments, thefluid source may comprise a bottle, canister, compressor system, or anyother suitable fluid delivery device. The fluid source 126 might containa quantity of liquid, preferably a refrigerant. For example, the fluidsource 126 can comprise one or more refrigerants, such as Freon,Refrigerant 12, Refrigerant 22, Refrigerant 134a, and the like. Thefluid source 126 can also comprise cryogenic fluids, such as liquidcarbon dioxide (CO₂) or nitrogen (N₂). In some embodiments, the workingfluid can be conveniently stored at room temperature. For example, CO₂or nitrogen is liquid at typical room temperatures when under sufficientpressure. In some non-limiting embodiments, the pressure of the storedfluid in the fluid source 126 will often be in the range of about 40bars to about 80 bars. In some embodiments, the fluid source 126 is abottle and the pressure in the bottle will be reduced during the moldingof preforms as fluid from the bottle is consumed. The fluid source 126can contain a sufficient amount of fluid so that the mold apparatus 122can be cooled for many cycles, as described below. The fluid source 126may have a regulator to control the flow of fluid into the fluid line130 and may comprise a compressor that can provide pressure to the fluidin the fluid line 130. Optionally, the working fluid of the temperaturecontrol system can comprise a combination of two or more of theaforementioned fluids to achieve the desired thermal characteristics ofthe working fluid. In some embodiments, the percentages of thecomponents of the working fluids can be selected based on the desiredtemperatures and pressures so that the components of the working fluiddo not solidify, for example. Other working fluids, such as water, canalso be employed to control the temperature of molding apparatus. Ofcourse, refrigerants can be used to more rapidly heat and/or cool themold apparatus and associated molded articles as compared tonon-refrigerants, such as water.

As used herein, the term “refrigerant” is a broad term and is used inits ordinary sense and refers, without limitation, to non-cryogenicrefrigerants (e.g., Freon) and cryogenic refrigerants. As used herein,the term “cryogenic refrigerant” is a broad term and is used in itsordinary sense and refers, without limitation, to cryogenic fluids. Asused herein, the term “cryogenic fluid” means a fluid with a maximumboiling point of about −50° C. at about 5 bar pressure when the fluid isin a liquid state. In some non-limiting embodiments, cryogenic fluidscan comprise CO₂, N₂, Helium, combinations thereof, and the like. Insome embodiments, the cryogenic refrigerant is a high temperature rangecryogenic fluid having a boiling point higher than about −100° C. atabout 1.013 bars. In some embodiments, the cryogenic refrigerant is amid temperature range cryogenic fluid having a boiling point betweenabout −100° C. and −200° C. In some embodiments, the cryogenicrefrigerant is a low temperature range cryogenic fluid having a boilingpoint less than about −200° C. at about 1.013 bars.

The heat load capabilities of a temperature control system using anon-cryogenic fluid may be much less than the heat load capabilities ofa temperature control system using cryogenic fluid. Further,non-cryogenic refrigerants may lose its effective cooling ability beforeit reaches critical portions of the mold. For example, Freon refrigerantmay be heated and completely vaporized after it passes through theexpansion valve but before it reaches critical mold locations and, thus,may not effectively cool the mold surfaces. The temperature controlsystems using cryogenic fluid can provide rapid cooling and/or heatingof the molding surface of the mold apparatus to reduce cycle times andincrease mold output.

In one embodiment, a fluid source inlet 128 of the fluid line 130 isconnected to the fluid source 126, and the fluid line 130 has an outlet134 leading to mold apparatus 122. Fluid from the fluid source 126 canpass through the fluid source inlet 128 into the fluid line 130 and outof the outlet 134 to the mold apparatus 122. The fluid line 130 is aconduit, such as a pipe or hose, in which pressurized fluid can pass.For example, in the illustrated embodiment of FIG. 8, fluid in the fluidline 130 is a liquid refrigerant at a pressure of about 40 bars to about80 bars.

Fluid from the fluid line 130 passes through the mold apparatus 122 tocontrol the temperature of the mold apparatus 122. In some embodiments,the fluid passes through one or more flow control devices (e.g.,pressure reducing elements, valves, and the like) located upstream of orwithin the mold apparatus 122. The flow control devices receive thefluid (preferably a liquid) at a high pressure and output a low pressureand temperature fluid (e.g., gas or gas/liquid mixture) to one or moreflow passageways in the mold apparatus 122. As shown in FIG. 10, forexample, the fluid can pass through a plurality of pressure reducingelements 212 in into a plurality of fluid passageways or channels 204 toselectively control the temperature of the preform. The fluidcirculating through the mold apparatus of FIG. 10 cools the warm melt toform a multilayer preform.

As used herein, the term “pressure reducing element” is a broad term andis used in its ordinary sense and refers, without limitation, to adevice configured to reduce the pressure of a working fluid. In someembodiments, the pressure reducing element can reduce the pressure ofthe working fluid to a pressure equal to or less than a vaporizationpressure of the working fluid. The working fluid can comprise arefrigerant (e.g., a cryogenic refrigerant or a non-cryogenicrefrigerant). In some embodiments, the pressure reducing elements are inthe form of pressure reduction or expansion valves that causevaporization at least a portion of the working fluid passingtherethrough. The pressure reducing element can have a fixed orifice orvariable orifice. In some embodiments, the pressure reducing element canbe a nozzle valve, needle valve, Joule-Thomson expansion valve, or anyother suitable valve for providing a desired pressure drop. For example,a Joule-Thomson expansion valve can recover work energy from theexpansion of the fluid resulting in a lower downstream temperature. Insome embodiments, the pressure reducing element vaporizes an effectiveamount of the working fluid (e.g., a cryogenic fluid) to reduce thetemperature of the working fluid such that the working fluid cansufficiently cool an article within a mold to form a dimensionallystable outer surface of the article. In some embodiments, the pressurereducing elements can be substituted with flow regulating elements(e.g., a valve system) especially if the working fluid is anon-refrigerant, such as water.

With reference again to FIG. 8, after the working fluid passes throughthe mold apparatus 122, the fluid passes through the inlet 136 andthrough the fluid line 140 and out of an outlet 144 to the exhaustsystem 148. The fluid line 140 is a conduit, such as pipe or hose, inwhich pressurized fluid can pass. In some embodiments, the fluid in thefluid line 140 is at a pressure less than about 10 bars, 5 bars, 3 bars,2 bars, and ranges encompassing such pressures. Of course, the pressureof working fluid may be different depending on the application.

The exhaust system 148 can receive and discharge the fluid from thefluid line 140. The exhaust system 148 can include one or more valvesthat can control the pressure of the fluid in the fluid line 140 and theamount of fluid emitted from the temperature control system 120. Theexhaust system 148 can include one or more fans and/or vents to furtherensure that the fluid properly passes through the temperature controlsystem 120. Preferably, the fluid is in the form of a gas that isdischarged into the atmosphere by the exhaust system 148. Thus, fluidfrom the fluid source 126 passes through the fluid line 130, the moldapparatus 122, the fluid line 140, and out of the exhaust system 148into the atmosphere. Preferably, the working fluid of the temperaturecontrol system 120 is a refrigerant, including cryogenic refrigerantslike nitrogen, hydrogen, or combinations thereof. These fluids can beconveniently expelled into the atmosphere unlike some other refrigerantswhich may adversely affect the environment.

FIGS. 9A-9L depict additional embodiments of temperature control systemsfor controlling the temperature of mold apparatuses. These temperaturecontrol systems may be generally similar to the embodiment illustratedin FIG. 8, except as further detailed below. Where possible, similar oridentical elements of FIGS. 8-9L are identified with identical referencenumerals.

FIG. 9A schematically illustrates a temperature control system 150,which is a closed loop system designed to control the temperature of themold apparatus 122 during preform manufacturing. The temperature controlsystem 150 has a fluid source 152 in communication with the moldapparatus 122. The mold apparatus 122 is in communication with a unit156, which is in communication with the fluid source 152. To cool themold apparatus 122, the working fluid can flow clockwise as indicated bythe arrow heads.

The fluid source 152 is connected to an outlet 170 of a fluid line 166and is connected to the source inlet 128 of the fluid line 130. Thefluid source 152 receives fluid from the fluid line 166 and deliversfluid to the fluid line 130. The fluid source 152 can store the workingfluid before, during, and/or after a production cycle.

As illustrated in FIG. 9A, the fluid line 130 is connected to the fluidsource 152 and the mold apparatus 122 in the manner described above. Thefluid line 140 is in fluid communication with the mold apparatus 122 andthe unit 156. The mold inlet 136 of the line 140 is connected to themold apparatus 122, and the outlet 144 of the line 140 is connected tothe unit 156. Fluid passes from the mold apparatus 122 into the inlet136 and through the fluid line 140 to the outlet 144. The fluid thenpasses through the outlet 144 and into the unit 156.

The unit 156 can recondition the fluid so that the fluid can beredelivered to the mold apparatus 122 for continuous flow through thetemperature control system 150. The unit 156 can include a compressorand/or heat exchanger. The fluid can flow through a compressor whichpressurizes the fluid and then flows through a heat exchanger (e.g., acondenser) that reduces the temperature of the pressurized fluid. Insome instances, the terms “heat exchanger” and “condenser” can be usedinterchangeably herein. Preferably, the unit 156 outputs a lowtemperature liquid to an inlet 168 of the fluid line 166. Fluid from theunit 156 can therefore pass through the fluid line 166 into the fluidsource 152 by way of the outlet 170.

The unit 156 can change modes of operation to heat the mold apparatus122, and the molded articles disposed therein. The working fluid canflow counter-clockwise through the temperature control system 150 toheat the mold apparatus 122. In one embodiment, the unit 156 receivescool fluid (preferably a liquid) from the fluid line 166 and delivers ahigh temperature gas or gas/liquid mixture, as compared to the coolliquid, to the fluid line 140. The high temperature fluid can heat themold apparatus 122 and article disposed therein. The unit 156 can thusinclude an evaporator and/or compressor for heating the working fluid.Thus, the unit 156 can be used to change the mode of operation to heator cool the mold apparatus 122 as desired.

With continued reference to FIG. 9A, the temperature control system 150can cool at least a portion of the mold apparatus 122, which in turncools the plastic in the mold apparatus 122. In one embodiment, thefluid source 152 delivers refrigerant, such as cryogenic fluid(preferably liquid carbon dioxide or nitrogen), to the fluid line 130and the mold apparatus 122.

The liquid passes through a portion of the mold apparatus 122 and isdelivered to one or more pressure reducing elements 212 (see FIG. 10).The pressure reducing elements 212 preferably receive the liquid at ahigh pressure and output fluid (e.g., gas or gas/liquid mixture) at alow temperature to the channels in the mold apparatus 122. The pressurereducing element 212 can reduce the temperature of the working fluidpassing therethrough. The fluid passes through and cools portions of themold apparatus 122, thereby cooling the polymer in the mold apparatus.

As shown in FIG. 9A, the mold apparatus 122 delivers the heated fluid tothe fluid line 140, which, in turn, delivers the fluid to the unit 156functioning as a compressor and condenser. The unit 156 outputs fluid inthe form of a low temperature liquid to the fluid line 166 and thesource 152.

In some embodiments, including the illustrated embodiment of FIG. 9A,the temperature control system 150 can have an optional a feedbacksystem 231 for delivering heated fluid from the mold apparatus 122 backinto and through the mold apparatus 122. In operation, fluid in thefluid line 140 passes through the feedback system 231 to mold apparatus122 via a feedback line 232. Preferably, the temperature of the fluid inthe feedback line 232 is at a temperature higher than the temperature ofthe fluid in the fluid line 130. Different portions of the moldapparatus 122 can be maintained at different temperatures by utilizingboth the fluid from the fluid line 130 and the feedback line 232. Thefluid in the feedback line may or may not be at a temperature of themelt deposited into the mold apparatus. One or more valve systems can bedisposed along the lines 130, 232 to regulate the flow of fluid throughthe mold apparatus 122. In some embodiments, the heating of the moldapparatus 122 by the utilizing the fluid from the feedback line 232 canbe performed when the fluid flow from the source 152 to the moldapparatus 122 is reduced or stopped. In some embodiments, the heatedfluid from the feedback line 232 can be used to reduce the rate ofcooling of the melt in the mold apparatus 122 to, for example, produce ahigh degree of crystallinity in the molded article. A variety oftemperature distributions can be achieved in the mold by utilizingworking fluids at different temperatures.

As discussed above, the temperature control system 150 can also heat atleast a portion of the mold apparatus 122 by circulating the workingfluid in the counter-clockwise direction. In one embodiment, the fluidsource 152 delivers fluid to the fluid line 166, which delivers thefluid to the unit 156. The unit 156 can function as a compressor and canincrease the temperature of the working fluid. In some embodiments, theunit 156 can receive a fluid (e.g., a two-phase working fluid) from theline 162. The temperature of the two-phase working fluid can beincreased by the unit 156 and then delivered to the line 140.

The unit 156 delivers heated fluid (e.g., a high temperature gas orgas/liquid mixture) to the fluid line 140. The fluid is then deliveredto and passes through the mold apparatus 122. The fluid passing throughthe passageways in the mold apparatus 122 heats one or more portions ofthe mold, which in turn heats or reduces the rate of cooling of thepolymer in the mold apparatus 122. The fluid is cooled as it passesthrough the mold apparatus 122 and is delivered to the fluid line 130,which delivers the cooled fluid to the fluid source 152. The fluidsource 152 then delivers the fluid to the fluid line 166 as describedabove. Thus, fluid flows in one direction through the temperaturecontrol system 150 to cool the mold apparatus 122 and flows in theopposite direction through the temperature control system 150 to heatthe mold apparatus 122. Further, the flow of fluid can be reversed oneor more times during preform production to heat (e.g., reduce the rateof cooling of the melt) and cool the mold repeatedly as desired.

The temperature control system 150 can have a device (not shown) forensuring that the pressure in the mold apparatus 122 remains at asufficiently low pressure. For example, the device can be a safetyvalve, blow off valve, or rupture disk that will prevent the pressure inthe mold apparatus 122 from reaching critical limits, especially as theworking fluid is heated within the mold apparatus 122 and undergoes aphase change (e.g., from liquid to gas).

If the working fluid passing through the mold apparatus 122 is atwo-phase fluid, the two-phase fluid can remain at a generally constanttemperature. In some embodiments, the two-phase liquid/gas mixture canbe at a generally constant pressure, while absorbing heat and remainingat a relatively low temperature so long as both liquid and gas phases ofthe working fluid are present. That is, the working fluid in the mold(e.g., in the fluid channels) can remain at a somewhat constanttemperature as long at least some of the working fluid is in a liquidstate. Additionally, the size of the channel can increase in thedownstream direction to limit or prevent a temperature increase of theworking fluid as the working fluid is vaporized. If liquid (e.g.,chilled water) is circulated through a mold, the temperature of theliquid may increase in the downstream direction and, thus, may produce adeclining cooling efficiency in the downstream direction.Advantageously, the mold apparatus 122 can be cooled by the two-phasemixture that is at a generally constant temperature throughout the moldapparatus 122 for enhanced thermal efficiency and/or more uniformcooling of the molded article.

In some embodiments of operation the fluid source 152 stores arefrigerant, such as cryogenic fluid in the form of carbon dioxide, at atemperature of about 20° C. and at a pressure of about 57 bar. Thetemperature of the fluid within the fluid source 152 can be controlledby increasing or decreasing the pressure applied to the fluid. Forexample, the fluid source 152 can contain carbon dioxide at a pressureof 80 bar and a temperature of about 25° C. If the pressure of thecarbon dioxide is lowered to 20 bar, the liquid carbon dioxide mayvaporize and lower the temperature of the liquid/gas mixture to about−20° C., so long as the cryogenic fluid comprises liquid carbon dioxide.The carbon dioxide two-phase fluid can be passed, preferably at arelatively high flow rate, through the mold apparatus 122. The high flowrate enhances wall contact, and the vaporization causes a high degree ofturbulence resulting in effective heat transfer between the walls of thepassageway and the working fluid. Of course, other working fluids can beused to control the temperature of the mold apparatus 150 in a similarmanner.

The proportion of liquid phase of the working fluid can be increased toincrease heat transfer to the working fluid. For example, a second fluidin the liquid phase can have a freezing point so low that the secondfluid will be a stable liquid at most of all of the temperatures andpressures experienced during the cooling process. The second fluid canincrease the rate of cooling of the polymer in the mold apparatus 122.The first fluid and the second fluid can be delivered together to themold apparatus 122. The first fluid can vaporize (at least partially)while the second fluid remains a liquid. Additional fluids with otherfreezing points can be used control the temperature of the moldapparatus 122 for a desired application. In view of the presentdisclosure, a skilled artisan can select the number and types of workingfluids to achieve the desired thermal characteristics of the workingfluid. In some embodiments, a plurality of working fluids can beutilized, wherein the working fluids can be selected to enhance mixingof the fluids. In some embodiments, the densities of two or more of theworking fluids can be substantially similar to each other to promoteeven mixing and cooling. However, in some embodiments, the densities ofthe working fluids can be substantially different from each other.

The fluid source of the temperature control systems can comprise aplurality of fluid sources. Each of the fluid sources can contain adifferent working fluid. For example, although not illustrated, thetemperature control system 150 of FIG. 9A can have a second fluid sourcecontaining a second fluid. The second fluid can have a freezing pointthat is higher than the temperature of the vaporized fluid from thefirst fluid source 152, as discussed above. It is contemplated thatadditional fluid sources can be added to any of the fluid systemsdescribed herein. Accordingly, any number of fluid sources and workingfluids can be used to control the temperature of the mold apparatus.

FIG. 9B illustrates a modified temperature control system. Thetemperature control system 150 of FIG. 9B can have a working fluid(e.g., a refrigerant, cryogenic fluid, and the like) that circulates theclosed loop system. The working fluid can flow in the clockwisedirection through the system 150 to provide chilled fluid to the moldapparatus 122. The fluid can flow in the counter-clockwise direction toprovide a heated fluid to the mold apparatus 122.

Fluid can pass through the fluid line 130 to the pressure reducingelement 212. The pressure reducing element 212 can comprise one or morevalves adapted to produce a change in temperature of the working fluid.The illustrated pressure reducing elements cause a pressure drop of theworking fluid, thereby reducing the temperature of the fluid. Thepressure drop across the pressure reducing element 212 can be increasedto increase the temperature drop. In some embodiments, the pressurereducing element 212 is configured to reduce the pressure of therefrigerant to a pressure equal to or less than a vaporization pressureof the working fluid. When a fluid (e.g., a refrigerant) passes througha pressure reducing element 212, at least portion of the refrigerant isvaporized. The amount of fluid that is vaporized can be selected toachieve a desired temperature change in the working fluid. The fluid inthe line 176 can thus comprise a two-phase fluid (e.g., a gas/vapormixture), although the fluid in the line 176 can comprise mostly orentirely a gas phase fluid. The fluid line 176 can be insulated tominimize temperature increases of the working fluid before the workingfluid cools a material disposed in the mold apparatus 122.

With continued reference to FIG. 9B, the low pressure fluid outputtedfrom the pressure reducing element 212 then passes through a fluid line176 and enters the mold apparatus 122. Preferably, the fluid enters themold apparatus 122 as a low pressure and low temperature two-phasemixture comprising liquid and gas. In the mold apparatus 122, heat fromthe mold apparatus 122 is transferred to the two-phase mixture such thatsome of the liquid component of the mixture is vaporized as a result ofthe heat transfer. The working fluid then passes through the fluid line140 to the unit 156, which comprises a compressor 149 a and condenser149 b. The compressor 149 a compresses, preferably adiabatically, thefluid to produce a saturated vapor. The saturated vapor is then passedto the condenser 149 b. The condenser 149 b can be a heat exchanger thatcondenses the fluid as heat is transferred from the working fluid to theenvironment. The fluid then passes through the fluid line 130 and thepressure reducing element 212 to repeat the process for continuous moldcooling. The flow of the working fluid can be continuous, intermittent,etc.

The temperature control system 150 can include an optional bypass system178 that can be used to obtain the desired characteristics of the fluiddelivered to the mold apparatus 122. In the illustrated embodiment, thebypass system 178 can have a fluid line 180 that is connected to thefluid line 130 and a fluid line 182 that is connected to the fluid line176. The high pressure fluid in the fluid line 130 can pass through thefluid line 180 and the low pressure fluid in the fluid line 176 can passthrough the fluid line 182. A valve system 188 can independently controlthe flow of fluid through the lines 180, 182 to adjust the pressure andtemperature drop across the pressure reducing element 212. The fluidfrom the lines 180, 182 can be delivered along the line 230, therebybypassing the mold apparatus 122. Alternatively, the bypass system 178can deliver heated downstream fluid in the line 140 to the moldapparatus 122. Heated fluid can be drawn through the line 230 to thevalve system 188. The valve system 188 can deliver the heated fluiddirectly to the mold or to the line 176 (as shown). In some embodiments,the valve system 188 comprises one or more flow regulating valves andone or more pumps or compressors. Thus, the bypass system 178 can beused to vary the pressure, temperature, and/or flow rate of the fluidthat is delivered to the mold apparatus 122.

The fluid line 182 can also deliver fluid directly to the mold apparatus122. Although not illustrated, the fluid line 182 can be connected tothe mold apparatus 122. Heated fluid in the line 140 can flow throughlines 230, 182 and into fluid channels in the mold apparatus 122. Theheated fluid can be passed through the mold apparatus 122. The heatedfluid can heat the mold apparatus 122 as the cool fluid from the line130 is passed through the mold apparatus 122. Thus, portions of the moldapparatus 122 can be heated by a heated fluid while other portions ofthe mold apparatus 122 are heated with a cooled fluid. In someembodiments, the flow of cooled fluid from the line 130 is reduce orstopped as the heated fluid from the line 182 flows through the moldapparatus. In operation, the cooled fluid can flow through the moldapparatus 122 to cool melt disposed within the mold apparatus 122. Thevalve system 188 can stop the flow of heated fluid through the line 182and the mold apparatus 122. After the molded article is removed from themold apparatus 122, heated fluid can be passed through the valve system188, the line 182, and into mold apparatus 122. The heated fluid canlimit the formation of condensation and/or heat the temperature of themold surfaces to facilitate the injection of melt into the mold cavityof the mold apparatus 122.

With respect to FIG. 9C, the temperature control system 183 has a moldsection 122 b that comprises one or more temperature control elements181. As used herein, the term “temperature control element” is a broadterm and is used in its ordinary sense and refers, without limitation,to a passageway, channel, temperature control rod (e.g., heating/coolingrods), heaters (e.g., resistance heaters), combinations thereof, and thelike. Temperature control elements can be positioned within molds(including injection molds, compression molds, stretch blow molds, andthe like) to control the temperature of the mold. The temperaturecontrol elements can be strategically placed in the mold for a desiredtemperature distribution. For example, to increase thermally efficiency,the temperature control elements can be mold towards molding surfaces ofthe molding apparatus 122.

The illustrated temperature control element 181 is in the form of afluid passageway. The fluid passageway 181 can comprise a plurality offluid channels, such as the fluid channels 204 illustrated in FIG. 10.The working fluid, preferably partially vaporized, in the passageway 181absorbs heat delivered by the mold section 122 b, which is heated by thehot polymer within the mold apparatus 122. The working fluid can flow ata constant or variable flow rate depending on the application.

The mold section 122 a can likewise have one or more temperature controlelements similar to or different than the temperature control element ofthe mold section 122 b. In some embodiment, at least a portion of themold section 122 b can be formed of a high heat transfer material. Thehigh heat transfer material can be at a location along the fluidpassageway 181 where rapid cooling is especially desirable. The highheat transfer material can be proximate to or near the molding surfacesof the mold apparatus 122 to maximize heat transfer. The high heattransfer material can also form the molding surfaces that contact themelt and subsequently formed article, although other configurations canbe used. The high heat transfer material and the temperature controlelement 181 in combination can rapidly and efficiently control thetemperature of the mold apparatus 122. However, the mold can also beformed partially or entirely of low heat transfer materials.

The temperature control system 183 can operate as an open loop system,closed loop system, and combinations thereof. In one mode of operation,the system 183 operates as an open loop system. The working fluid canflow through the passageway 181 and into the lines 136, 140 and can bevented off by the exhaust system 148. A valve system 179 can be used toselectively control the flow of fluid to the exhaust system 148. Forexample, the valve system 179 can be operated to maintain a targetpressure in the fluid lines and/or mold apparatus 122. The targetpressure can be equal to or above a predetermined pressure drop acrossthe pressure reducing element 212. For example, if the working fluid isliquid carbon dioxide, a pressure drop across the pressure reducingdevice 212 that less than 5 bar could lead to the formation of solidcarbon dioxide. The valve system 179 can be operated to ensure that thepressure of the working fluid maintains desirable operation of thesystem.

In some modes of operation, the system 183 can be operated as aclosed-loop system. The system 183 can comprise a closed-loop portion161 that feeds the working fluid back to the fluid source 152. Thetemperature control system 183 can thus be operated as a closed loopsystem or a closed loop system depending on whether the working fluid issuitable for venting to atmosphere.

With continued reference to FIG. 9C, the closed-loop portion 161 cancomprise a compressor 149 a and a condenser 149 b. The heated fluid inthe line 136 can flow through the line 186 (shown in dashed line) to thecompressor 149 a. The compressor 149 a can be series with the condenser149 b to reduce the temperature of the fluid delivered to the source152. The compressor 149 a and the condenser 149 b can cooperate todeliver fluid at a desired temperature and pressure to the fluid source152 through the line 189. Preferably, the working fluid is delivered tothe source 152 at the original pressure and temperature of the fluid inthe source 152. In some embodiments, the fluid source(s) can be removedfrom the temperature control system and the working fluid can be storedin the fluid lines.

The illustrated closed-loop system 161 can have an optional bypasssystem 163 that delivers heated fluid to some location upstream of themold apparatus 122. The illustrated bypass system 163 has at least onevalve system 163 a (e.g., a flow control valve) positioned along theline 163 b. The valve system 163 a can be operated to let warmcompressed fluid flow through the line 163 b. The warm fluid from theline 163 b is mixed with the cool fluid outputted by the pressurereducing element 212. The ratio of the fluid from the line 163 b andfluid from the pressure reducing element 212 can be selected to achievea target fluid temperature of the fluid circulating through the moldapparatus 122. Thus, the bypass system 163 can be used to selectivelycontrol the temperature of the fluid delivered to the mold apparatus122.

The pressure reducing element 212 can be disposed external to the moldapparatus 122 as shown in FIG. 9C. However, the pressure reducingelement 212 can be positioned within the mold apparatus 122. As shown inFIG. 9D, for example, the pressure reducing element 212 is disposedwithin the mold apparatus 122. The pressure reducing element 212 can bepositioned any suitable point along the passageway 181. For example, thepressure reducing element 212 can be positioned at the entrance of thepassageway 181, inside the passageway 181. However, the pressurereducing element 212 can be positioned inside a mold plate leading tothe passageway 181, or any other suitable location.

FIG. 9E illustrates a temperature control system 183 that has at leastone flow separator 131. The line 136 delivers a fluid (e.g., a heatedgas/liquid mixture) from passageway 181 to the phase separator 131which, in turn, delivers the gas phase fluids to the line 130 a andliquid phase fluids to the line 130 b. The flow separator 131 can be amembrane separation unit or other suitable device for separating liquidand gas flows.

The flow separator 131 can have a membrane that allows certainsubstances to pass therethrough at a first flow rate and othersubstances to pass therethrough at a second flow rate different than thefirst flow rate. For example, and more particularly, such membraneseparation unit can be provided with a membrane that allows liquids andgases to pass therethrough at different rates. The effect is that theretentate liquid (e.g., liquid that do not permeate through themembrane) remains on one side of the membrane. The permeate gases passthrough the membrane. In this manner, the liquid and gas component ofthe working fluid are separated. The gas and fluid are then delivered tothe lines 130 a, 130 b. It is contemplated that other types of flowseparators can be employed.

A compressor 124 a and a heat exchanger 127 a are positioned along theline 130 a so as to deliver fluid to the source 152 a at substantiallythe same pressure and temperature as the fluid contained in the source152 a. The flow separator 191 delivers the liquid component to the line130 b. The liquid is delivered to a compressor 124 b, heat exchanger 127b, and returned to the fluid source 152 b. In some embodiments, a singleheat exchanger can be used to cool both the gas phase component andliquid phase components from the flow separator 191.

Fluids from the fluid sources 152 a, 152 b flow along the lines 130 a,130 b, respectively, and are preferably mixed at the junction 193. Thefluid source 152 a comprises a first fluid. The first fluid ispreferably a cryogenic fluid that will at least partially vaporize as itpasses through the pressure reducing element 212. The fluid source 152 bpreferably comprises a second fluid which remains a stable liquid as itpasses through the pressure reducing element 212. Thus, the passageway181 can contain one or more different fluids. The first fluid can have aliquid component that vaporizes as it absorbs heat from the moldapparatus 122. The second fluid from the source 152 b can remain aliquid, thus maintaining high thermal loading capabilities.Alternatively, both fluids can vaporize as they circulate through themold apparatus 122.

FIG. 9F shows the example of a temperature control system 183 thatcomprises a mold apparatus 122 having portions with different thermalconductivities. The illustrated mold apparatus 122 comprises a firstsection 199 comprising a first material and a second section 310comprising a second material. In some embodiments, the second materialpreferably has a thermal conductivity greater than the first material.In some embodiments, the second section 310 comprises a high heattransfer material. The first section 199 can surround and thermallyinsulate the second section 310 to minimize heat losses from the moldapparatus 122. For example, the first section 199 can be in the form ofa mold plate that houses the second section 310. The mold plate cancomprise steel (e.g., stainless steel or other steel alloys) or otherlow thermally conductive material.

The passageway 181 can pass through the first section 199 and/or thesecond section 310. The position of the passageway 181 in the moldapparatus 122 can be selected based on the desired cooling rates andheat distribution of the polymer in the mold apparatus 122.Additionally, the pressure reducing device 212 can be positionedexternal to the mold apparatus (shown), within the first section 199,within the second section 310, or another suitable location for reducingthe pressure of the working fluid.

With respect to FIG. 9G, the temperature control system 183 comprisesone or more sensors coupled to the mold apparatus 122. In someembodiments, the sensors are configured to detect and send a signalindicative of the temperature of the mold apparatus 122. In someembodiments, including the illustrated embodiment, a sensor 167 ispositioned somewhat between the passageway 181 and the polymer in themold apparatus 122. In some embodiments, the sensor 167 is interposeddirectly between the mold cavity and the passageway 181. In someembodiments, the sensor 167 is positioned near the molding surface ofthe mold apparatus 122 for accurately measuring the temperature of themolding surfaces.

The sensor 167 can send a signal directly or indirectly to a controller165. The controller 165 can have a stored control program or map and canselectively control the valve 169 based on the signal from the sensor167. The controller 165 can selectively control the valve 169 based on,for example, absolute mold temperatures, rate of temperature changes,and/or the like to achieve the desired cycle and preform finish. Anynumber of sensors 167 can be positioned in the mold apparatus 122 tomeasure the temperature of the mold apparatus 122. A plurality ofsensors can be positioned throughout the mold is measured thetemperature of the mold apparatus 122 at various locations.

The valve 169 can be any suitable flow regulator or valve forcontrolling the flow of fluid to the fluid line 184. The valve 169 canbe a solenoid valve which inhibits flow of the fluid coming from thefluid source 152 by way of the line 130. In other embodiments, the valve169 comprises a needle valve (preferably an adjustable needle valve).The valve 169 can provide a pressure drop so that a gas/liquid mixtureis delivered to the line 184, which leads to the passageway 181 of themold section 122 b.

In some embodiments, at least a portion of the line 184 is disposedwithin the first section 199 in the form of a mold plate. The line 184can be thermally insulated to inhibit the absorption of heat to theworking fluid from the mold apparatus or the surrounding environment.The line 184 can be insulated with stainless steel, phenolic, nomex,and/or other suitable low heat transfer material for enhancing thermalisolation of the fluid flowing through the line 184. In someembodiments, the line 184 is insulted by an insulating jacket. Theinsulating jacket can comprise a polymer, foam, or a metal (e.g., steeland its alloys, such as stainless steel). Advantageously, an insulatorcan limit or prevent the deposition of moisture (e.g., condensation) onfluid lines. The insulated line 184 reduces or limits temperaturechanges of the working fluid passing through the line 184 for increasedthermal efficiency. As the fluid passes through the passageway 181 itabsorbs heat coming from the polymer, which causes additionalvaporization of the fluid. As described above, the heated fluid passesthrough the line 136 to the unit 156, which pressurizes the workingfluid. The fluid can have a somewhat elevated temperature. The heatexchanger 197 receives and cools the fluid, which lead to finalcondensation. The condensed fluid is returned to the source 152. Thevalve 163 a of the bypass system 163 is preferably closed when theworking fluid flows clockwise through the temperature control system 183and cools the mold apparatus 122.

The temperature of the mold apparatus 122 can be raised for at least aportion of the production cycle. For example, the temperature of themold section 122 can be raised to prevent the formation of condensationon the mold surfaces. The temperature of the mold surfaces can be raisedbefore injection of the polymer into the mold cavity in order to preventformation of moisture on the mold surfaces forming the mold cavity.

To warm the mold apparatus 122, the controller 165 can reduce or stopthe flow of fluid through the valve 169 and can permit fluid flowthrough the valve 163 a of the bypass system 163. The warm compressedfluid in the bypass line 163 b is fed back into the passageway 181 toheat the molding surfaces, and preferably minimizing the formation ofcondensation.

When the mold surfaces of the mold apparatus 122 are exposed toatmospheric air, the temperature of the mold surfaces can be maintainedat or above a dew point temperature to limit the formation ofcondensation. The controller 165 can operate the valves 163 a, 169 tomaintain the temperature of the mold surfaces at a preset temperaturepreferably at or above the dew point. In some embodiments, the moldsurfaces can be preheated to aid the spreading of melt through the moldcavity. After the melt fills the mold cavity, the mold surfaces can becooled at various rates to form articles with a particular finish.

The controller 165 can close the valve 163 a and open the valve 169 tocool the mold surfaces before, during, and/or after the polymer has beeninjected into the mold cavity of the mold apparatus 122. The fluid inthe line 184 can be at a relatively low pressure because the valve 163 ais closed, thus introducing a fluid mixture with minimum temperature andmaximum cooling efficiency to the channel 181.

High conductivity materials can be used for rapid temperature changes ofthe mold apparatus 122. During the molding process, if the mold surfacesare relatively cool, the leading portions of the melt can travel thefurthest distance along the mold cavity and thus may be significantlycooler than the other portions of the melt (e.g., the polymer in thevicinity of the gate). The non-uniform cooling rates can lead to lessthan optimum polymer properties. Thus, during portions of the productioncycle, certain sections of the mold apparatus 122 can be cool forportion(s) of the molding process and relatively warm for otherportion(s) of the injection process. To reduce production cycle times,the temperature changes in the mold can be relatively fast. Thetemperature and/or flow rate of the cooling fluid can vary considerablyduring the production cycle for different applications.

The materials forming the mold apparatus 122 can be chosen to achievethe desired amount of crystallinity in the article. For example, thepolymer adjacent to the second section 310 can a can be rapidly cooledto form a polymer with a low degree of crystallinity. Thus, the polymernear or contacting the second section 310 can comprise mostly orentirely amorphous material. The first portion 199 can comprise amaterial with a lower thermal conductivity to reduce the rate cooling ofthe polymer thereby increasing the degree of crystallinity of thepolymer. For example, the first portion 199 can be configured to form acrystalline neck finish of preform.

With reference to FIG. 9H, a temperature control system 183 isillustrated. The illustrated passageway 181 extends through the firstsection 199 and the second section 310. As discussed above, firstsection 199 can be formed of a material having a higher thermalconductivity than the second section 310 such that the first section 199cools the polymer at a lower rate than the second section 310. Inalternative embodiments, the second section 310 and the first portion199 can both be made of materials having similar conductivities. Forexample, the second section 310 and the first section 199 can comprisematerials having a high thermal conductivity. Low conductivity materials(e.g., inserts) can be positioned between the first section 199 and thesecond section 310 for thermal isolation. In some embodiments, thesecond section 310 and the first section 199 each comprises high heattransfer materials. Each of the second section 310 and first section 199can have one or more temperature sensors to measure the temperature ofthe mold apparatus 122.

With respect to FIG. 9I, the temperature control system 183 has apassageway 181 that may or may not pass through both sections 310, 199.Fluid from the fluid source 152 is delivered to a flow metering system155. The flow metering system 155 can be a dosing system that includes aplurality of valves that cooperate to delivered doses of fluid to themold apparatus 122. The illustrated flow metering system 155 can be usedto deliver a precise amount of fluid with desirable characteristics tothe mold apparatus 122. The flow metering system 155 can comprises afirst valve 169 a (e.g., a solenoid valve), a tank 157, and a secondvalve 169 b (e.g., a solenoid valve). The control lines 171 a, 171 bprovide communication between the control unit 165 and the valves 169 a,169 b, respectively. The controller 165 can operate the first valve 169a and the second valve 169 b to accurately fill the tank 157 with acertain amount of fluid. The control unit 155 can be any suitablecontroller for selectively operating the valves 169 a, 169 b.

To cool the mold apparatus 122, the control unit 165 opens the valve 169a and fluid is delivered to the dosing tank 157. After the dosing tank157 is filled with a desired amount of fluid, the control unit 165 opensthe valve 169 b and the fluid from the dosing tank 157 is delivered tothe line 184. The capacity of the dosing tank 157 can be selected basedon the desired amount of fluid delivered to the line 184. The tank 157can be partially or completely filled depending on the desired amount offluid delivered to the mold apparatus 122. Thus, a precise amount offluid can be delivered to the line 184 and ultimately to the moldapparatus 122.

The flow metering system 155 is able to produce a rapid sequence of“micro-pulses” of fluid that expands in the line 184 and the passageway181 to cool the mold apparatus 122. The sensor 167 monitors thetemperature of mold apparatus 122 and delivers a signal to control unit165. The control unit 165 determines the number and timing of doses thatare delivered to the line 184. The number of doses of fluid delivered tothe mold apparatus 122 can be increased or decreased to increased ordecrease rate of cooling in the mold apparatus 122. When the moldedarticle is demolded, the valve 169 b can limit or prevent thecirculation of working fluid through the mold apparatus 122 to minimizethe formation of condensation on the mold surfaces.

Optionally, the mold apparatus 122 can comprise one or more temperaturecontrol elements for heating portions of the molds. The illustrated moldapparatus 122 comprises a temperature control elements in the form of aheater 173 (FIG. 9I). The illustrated heater 173 is a resistance heaterpositioned within the mold apparatus 122. As such, the heater 173 canheat a desired portion of the polymer in the mold apparatus 122. In someembodiments, the heater 173 can heat (including reducing the rate ofcooling) a portion of mold apparatus 122 as the cooling fluid isdelivered through the passageway 181. Thus various portions of the moldapparatus 122 can be at any desired temperature. Other suitabletemperature control devices can also be used to control the temperatureof the mold apparatus 122.

A plurality of temperature control systems can be connected together. Asshown in FIG. 9J, the temperature control system 219 comprises aplurality of independent flow circuits. The illustrated temperaturecontrol system 219 comprises a first temperature control system 150′ anda second temperature control system 150″. The unit 156 can be a heatexchanger configured to exchange heat between the working fluids of thefirst temperature control system 150′ and the second temperature controlsystem 150″. In some embodiments, the first temperature control system150′ can be configured to cool a first mold apparatus 122′.

A second temperature control system 150″ can be used to cool the secondmold apparatus 122″ as the first temperature control system 150′ heatsthe mold apparatus 122′. The heated fluid delivered from the line 140 tothe unit 156 can be cooled by the fluid passing through the temperaturecontrol system 150′. The flows in the temperature control system 150′,150″ can be reversed to change the mode of operation of the systems150′, 150″.

The temperature control systems described herein can be combined andmodified to achieve the desired thermal performance. The fluid lines areschematically illustrated as a single line. However, the fluid lines cancomprise a plurality of lumen and/or a plurality of houses.

FIGS. 9K and 9L illustrate a plurality of mold apparatuses that areconnected by a connecting line 213. Fluid warmed in one mold apparatuscan be used to heat another mold apparatus. For example, cool fluid canbe used to cool a first mold apparatus. The fluid can be heated as itpasses through the first mold apparatus and then can be used to heat asecond mold apparatus. For example, the second mold apparatus can beheated when the article is removed from the second mold apparatus.During a second portion of the production cycle, fluid can be heated asit passes through the second mold apparatus and can then be used to heata first mold apparatus.

Any number of mold apparatuses can be connected together by any numberof fluid lines depending on, e.g., the production cycles. Theillustrated system comprises a first mold apparatus 122′ and a secondmold apparatus 122″ connected by a fluid line 213. In some embodiments,the line 217′ and mold apparatus 122′ can be part of a temperaturecontrol system described above. Similarly, the line 217″ and moldapparatus 122″ can be a part of a temperature control system describedabove.

With continued reference to FIG. 9K, during a first period of time, aworking fluid is delivered through the line 217′ to the mold apparatus122′ to cool at least one article therein. The working fluid is heatedas it passes through the mold apparatus 122′. The heated fluid can flowthrough the connecting line 213 to the mold apparatus 122″. The heatedfluid can then heat the mold apparatus 122″. The mold apparatus 122″ canbe heated to limit or prevent the formation of condensation on the moldsurfaces, heat the surfaces of the mold to enhance the flow of meltthrough a mold cavity, produce crystalline material, and the like.

During a second period of time, a working fluid is delivered through theline 217″ to the mold apparatus 122″ to cool at least one articletherein, as shown in FIG. 9L. The working fluid is heated as it passesthrough the mold apparatus 122″. The heated fluid can flow through theconnecting line 213 to the mold apparatus 122′. The heated fluid canthen heat the mold apparatus 122′. The mold apparatus 122′ can be heatedto limit or prevent the formation of condensation on the mold surfaces,heat the surfaces of the mold to enhance the flow of melt through a moldcavity, produce crystalline material, and the like.

The features, components, systems, subsystems, devices, materials, andmethods of the temperature control systems in FIGS. 8-9L can be mixedand matched by one of ordinary skill in this art in accordance withprinciples described herein. Additionally, one or more check valves,pressure sensors, flow regulators, fluid lines, temperature sensors,detectors, and the like can be added to the temperature control systemsas desired.

C. Methods and Apparatus for Injection Molding

Monolayer and multilayer articles (including packaging such as closures,preforms, containers, bottles) can be formed by an injection moldingprocess. One method of producing multi-layered articles is referred toherein generally as overmolding. Multilayer preforms can be formed byovermolding by, e.g., an inject-over-inject (“IOI”) process. The namerefers to a procedure which uses injection molding to inject one or morelayers of a material over an existing preform or substrate, whichpreferably was itself made by injection molding. The terms“overinjecting” and “overmolding” are used herein to describe themolding process whereby a layer of material is injected over an existingpreform. In an especially preferred embodiment, the overinjectingprocess is performed while the underlying preform has not yet fullycooled. Overinjecting may be used to place one or more additional layersof materials, such as those comprising barrier material, recycled PET,foam material, or other materials over a monolayer or multilayerpreform.

Molding may be used to place one or more layers of material(s) such asthose comprising lamellar material, PP, foam material, PET (includingrecycled PET, virgin PET), barrier materials, phenoxy typethermoplastics, combinations thereof, and/or other materials describedherein over a substrate (e.g., the underlying layer). In somenon-limiting exemplary embodiments, the substrate is in the form of apreform, preferably having an interior surface suitable for contactingfoodstuff. The temperature control systems can be utilized to controlthe temperature of preforms formed by these molding processes. Thetemperature control systems can also be used when forming a singlemonolayer preform, as described below in detail.

Articles made by a molding process may comprise one or more layers orportions having one or more of the following advantageouscharacteristics: an insulating layer, a barrier layer, a foodstuffcontacting layer, a non-flavor scalping layer, a high strength layer, acompliant layer, a tie layer, a gas scavenging layer, a layer or portionsuitable for hot fill applications, a layer having a melt strengthsuitable for extrusion. In one embodiment, the monolayer or multi-layermaterial comprises one or more of the following materials: PET(including recycled and/or virgin PET), PETG, foam, polypropylene,phenoxy type thermoplastics, polyolefins, phenoxy-polyolefinthermoplastic blends, and/or combinations thereof. For the sake ofconvenience, articles are described primarily with respect to preforms,containers, and closures.

FIG. 10 illustrates a preferred type of mold apparatus 132 for use inmethods which utilize overmolding. The mold apparatus 132 can form alayer on the preform 30 to form a multilayer preform, such as thepreform 50 of FIG. 3. The temperature control systems described hereincan be used to control the temperature of the mold apparatus 132, andthe other molds described below.

The mold apparatus 132 comprises two halves, a cavity section 192 and acore section 194. The cavity section 192 comprises a cavity in which thepreform is placed. The core section 194 and the cavity section 192 aremovable between a closed position and an open position. The preform canbe a monolayer preform (illustrated) or a multilayer preform. Thepreform 30 is held in place between the core section 194, which exertspressure on the top of the preform and the ledge 196 of the cavitysection 192 on which the support ring 38 rests. The neck portion 32 ofthe preform 30 is thus sealed off from the body portion of the preform30. Inside the preform 30 is the core 198. As the preform 30 sits in themold apparatus 132, the body portion of the preform 30 is completelysurrounded by a void space 200. The space 200 is formed by outer surfaceof the preform 30 and a cavity molding surface 203 of the cavity section192. The preform, thus positioned, acts as an interior die core in thesubsequent injection procedure, in which the melt of the overmoldingmaterial is injected through the gate 202 into the void space 200 toform an outer layer of the preform.

The cavity section 192 and/or the core section 194 have one or moretemperature control elements 204. The temperature control elements 204are in the form of a plurality of passageways or channels forcontrolling the temperature of the melt and the preform 30. Fluidsflowing through the channels 204 can, for example, cool the moldapparatus 132, which in turn cools the injected melt. In the illustratedembodiment of FIG. 10, the cavity section 192 has a plurality ofchannels 204 while the core section 194 also has a plurality of channels206. A plurality of pressure reducing elements 212 are positionedupstream of the channels 204, 206. The pressure reducing elements 212are positioned within the cavity section 192 and the core section 194.However, the pressure reducing elements 212 can be positioned outside ofthe cavity section 192 and/or the core section 194. In the illustratedembodiment, there is an upper outlet 134 and a lower outlet 134 thatdeliver fluid to the channels 206, 204, respectively.

With continued reference to FIG. 10, the mold outlets 134 can have aflow regulator 214 in fluid communication with the pressure reducingelements 212. The flow regulator 214 can be a valve system thatselectively controls the flow of fluid to the channels 204. A pluralityof conduits 216 can provide fluid flows between the flow regulator 214and the pressure reducing elements 212. Each flow regulator 214 canselectively permit or inhibit the flow of fluid from the outlet 134 intothe conduits 216 and into the mold apparatus 132. In one embodiment, theflow regulator 214 can be solenoid valve, either actuated electronicallyor pneumatically, to permit or inhibit the flow into the mold apparatus132. In various other embodiments, the flow regulator 214 can be a gatevalve, globe valve, or other suitable device that can control the flowof fluid. A controller (e.g., the controller 218 of FIG. 9A) can commandthe flow regulator 214 to permit or inhibit the flow of fluid to thechannels (e.g., channels 204 and/or 206). The flow regulator 214 canstop the flow of fluid through the mold apparatus 132 for intermittentfluid flow. Optionally, the flow regulator 214 can provide differentfluid flow rates to each of the conduits 216.

Fluid from the conduits 216 passes through pressure reducing elements212 and into the channels 204 in the mold apparatus 132. Although notshown, the outlet 134 can feed fluid directly to the pressure reducingelements 212. As discussed above, there can be a temperature drop acrossthe pressure reducing elements 212. In the illustrated embodiment ofFIG. 10, there is a pressure drop across the pressure reducing elements212 so that the temperature of the fluid in channels (e.g., channels204) is at or near a desired temperature. The temperature drop ispreferably caused by a reduction in pressure across the pressurereducing elements 212.

Advantageously, during operation of the temperature control system, thepressure of the working fluid (e.g., a cryogenic fluid such as nitrogen)can be substantially less than the pressure of non-cryogenic fluid(e.g., Freon). When the working fluid of the temperature control systemsis a cryogenic fluid such as supercritical carbon dioxide (CO₂) ornitrogen (N₂), the mold apparatus does not have to be able withstand thehigh pressures that are typical of non-cryogenic systems. Thus, the lowpressure molds cooled with cryogenic fluids may be less costly toproduce than the high pressure molds that are cooled with non-cryogenicfluids. Additionally, because the cryogenic fluid in the mold apparatusis at such a low pressure, there may be less leakage from the moldapparatus and/or other sections of the temperature control system. Thenon-cryogenic refrigerants based systems may require expensive hermeticseals to ensure that the working fluid does not escape to theenvironment.

With continued reference to FIG. 10, the working fluid can undergo aphase change as it passes through the pressure reducing elements 212. Aportion of the fluid can change phases, i.e. vaporize to gas, as itpasses through the pressure reducing elements 212 and the enthalpy ofthe gas can further cool the channels in the mold. In one embodiment, atleast a substantial portion of the liquid from the outlet 134 changes togas as it passes through the pressure reducing elements 212. In oneembodiment, a controller 218 (FIG. 9A) commands the pressure reducingelements 212 to increase or decrease the pressure change across thepressure reducing elements 212 in order to ensure the proper temperatureof fluid in the channels of the mold apparatus 132.

In some embodiments, for example, the fluid upstream of the pressurereducing elements 212 is liquid (e.g., liquid CO₂ or N₂) at about 40bars to about 80 bars. In some embodiments, the fluid upstream of thepressure reducing elements 212 is at a pressure of about 60 bars toabout 80 bars. In some embodiments, the fluid upstream of the pressurereducing elements 212 is at a pressure of 20 bars, 30 bars, 40 bars, 50bars, 60 bars, 70 bars, 80 bars, and ranges encompassing such pressures.The pressure of the liquid is reduced across the pressure reducingelement 212 such that at least a portion, preferably a substantialportion, of the liquid vaporizes resulting in fluid comprising gasdownstream of the pressure reducing elements 212. The gas in thechannels is preferably at 10 bars or less and will result in a reduceddownstream temperature of the fluid. In some embodiments, the pressureon the low side of the pressure reducing element is 2 bars, 4 bars, 5bars, 7 bars, 10 bars, 15 bars, and ranges encompassing such pressures.For example, in some non-limiting embodiments, the downstreamtemperature of the working fluid may less than about 10° C., 0° C., −5°C., −30° C., −60° C., −100° C., −150° C., −175° C., −200° C., and rangesencompassing such temperatures. Preferably, the temperature of the fluidcan be maintained at a suitable temperature by adjusting the pressure ofthe fluid in the channels 204, 206. In the illustrated embodiment, avalve 222 is disposed along the mold inlet 136 of the fluid line 140 andcan selectively permit or inhibit the flow of fluid such that the fluidin channels of the mold apparatus 132 is at the desired pressure andtemperature. A controller can therefore command the pressure reducingelements 212, 222 so that the temperature of the fluid in the channels204 is at the desired temperature.

With continued reference to FIG. 10, the pressure reducing elements 212can be proximate to the cavity molding surface 203 to ensure that thecavity molding surface 203 is maintained at a relatively lowtemperature. As such, the temperature of the fluid does notsubstantially change as it moves through the mold apparatus 132 betweenthe pressure reducing elements 212 and the channels 204. In someembodiments, the channels 204 are sized to permit expansion and furthercooling of the working fluid. For example, the channels 204 can beenlarged in the downstream direction to allow expansion of the workingfluid. It is contemplated that the pressure reducing elements 212 can bepositioned at other suitable locations for delivering fluid to thechannels within the mold apparatus 132. For example, the pressurereducing elements 212 can be positioned outside of the mold apparatus132 (e.g., see FIG. 9B).

The channels 204, 206 are located in the mold apparatus 132 such thatheat is transferred to the fluid flowing through the channels 204, 206to cool the mold apparatus 132. As used herein, the term “channel” is abroad term and is used in its ordinary sense and refers, withoutlimitation, to any structure or elongated passage that defines a fluidflow path for effectively controlling the temperature of a mold. In someinstances, the terms “channels” and “passageways” are usedinterchangeably herein. Liquids can flow along the length of thechannels for high thermal loads. In some embodiments, the channels canbe a diffusion passage configured to produce a pressure drop. Thediffusion channels can be positioned downstream of the pressure reducingelement. The channels can have varying cross sections along theirlengths. For example, the channels can have a cross sectional area thatincreases in one direction. In some embodiments, if a two-phase fluidflows through a channel, the cross sectional area of the channel canincrease in the downstream direction to accommodate an increase in thevolume of the fluid as some of the liquid component vaporizes due to theabsorption of heat. Thus, the working fluid may not rise in pressure dueto the absorption of heat. In some embodiments, however, the fluidchannels can have a somewhat constant cross sectional area or othersuitable configuration.

An inner portion 220 of the cavity section 192 is disposed between oneor more channels 204 and the cavity molding surface 203 and is designedto permit efficient heating or cooling of the cavity molding surface203. The terms “cavity molding surface” and “cavity surface” may be usedinterchangeably herein. In some embodiments, the inner portion 220 ofthe mold comprises a high heat transfer material to rapidly cool thematerial engaging the cavity molding surface 203.

As used herein, the term “high heat transfer material” is a broad termand is used in accordance with its ordinary meaning and may include,without limitation, low range, mid range, and high range high heattransfer materials. Low range high heat transfer materials are materialsthat have a greater thermal conductivity than iron. For example, lowrange high heat transfer materials may have a heat conductivity superiorto iron and its alloys. High range high heat transfer materials havethermal conductivity greater than the mid range materials. For example,a material that comprises mostly or entirely copper and its alloys canbe a high range heat transfer material. Mid range high heat transfermaterials have thermal conductivities greater than low range and lessthan the high range high heat transfer materials. For example, AMPCOLOY®alloys, alloys comprising copper and beryllium, and the like can be midrange high heat transfer materials. In some embodiments, the high heattransfer materials can be a pure material (e.g., pure copper) or analloy (e.g., copper alloys). Advantageously, high heat transfermaterials can result in rapid heat transfer to reduce cycle times andincrease production output. For example, the high heat transfer materialat room temperature can have a thermal conductivity more than about 100W/(mK), 140 W/(mK), 160 W/(mK), 200 W/(mK), 250 W/(mK), 300 W/(mK), 350W/(mK), and ranges encompassing such thermal conductivities. In someembodiments, the high heat transfer material has a thermal conductivity1.5 times, 2 times, 3 times, 4 times, or 5 times greater than iron.

To enhance temperature control, the temperature control elements can beused in combination with high heat transfer material. For example, oneor more temperature control elements can be positioned near or withinthe high heat transfer material to maximize heat transfer between themold surfaces and the temperature control elements. For example, thehigh heat transfer can form at least a substantial portion mold materialinterposed between the one or more temperature control elements and themolding surfaces.

The high heat transfer material may or may not form the molding surfacethat contact the melt. For example, a layer of material can bepositioned between the high heat transfer material and the moldingcavity. To protect the high heat transfer material, a thin layer ofmaterial (e.g., titanium nitride, hard chrome, and other materialsharder than the high heat transfer material) may be deposited on thehigh heat transfer material and form a hard molding surface 203. Such aprotective layer is preferably less than about 0.0254 mm (0.001 inches),0.127 mm (0.005 inches), 0.254 mm (0.01 inches), 1.27 mm (0.05 inches),2.54 mm (0.1 inches), and ranges encompassing such thicknesses. Theprotective layer can improve mold life while also providing rapid heattransfer from the melt to the high heat transfer material.

The high heat conductivity alloys can be used for rapid heating andcooling. The high heat conductivity alloys can achieve both high and lowtemperatures along the mold surfaces in contact with the polymer.Additionally, the high heat conductivity alloys can produce a generallyflat temperature profile over most of the mold wall for efficient heatflow. This allows for increased flexibility of mold design. For example,the temperature control elements can be moved away from the moldsurfaces without substantially effecting the cooling/heating capacity ofthe temperature control elements because heat can be rapidly conductedthrough the high heat transfer material.

Time from injection to demolding, which may strongly influence cycletime, can be different for mold cooling and post-cooling operations. Inthe absence of post-cooling, the preform has to remain in the mold untilthe bulk of the polymer has cooled to a temperature profile which willnot cause structural instability after demolding. After demolding, theperiphery of the preform is not actively cooled and is reheated by theheat coming from the warm interior of the article. Because the bulk ofthe polymer has to cool down and polymers can have low heatconductivity, the time to demold, and thus cycle time, can largelydepend on the preform dimensions (e.g., the preform's wall thickness).Thus, time to demold and cycle time can be increased as the preform'swall thickness is increased.

High conductivity mold materials can be employed to reduce cycle times.For producing preforms with higher wall thicknesses, high conductivitymold materials may produce a negligible reduction of the cycle time, asheat flow is dominated by the largest heat resistor, which in this caseis the bulk polymer itself. Nevertheless, molds comprising high heatconductive mold materials can be used for mold cooling processes.

If a post-cooling operation is utilized, demolding can be done at anearlier stage as structural stability of the molded article is primarilyneeded to withstand the mechanical forces during demolding. Thestructural stability molded article can be quickly demolded from themold. At the moment of demolding, due to the chilling effect of the moldwall the peripheral layers of the molded article have already fallen tolower temperatures while the interior of the article is a soft liquid.For example, there can be a steep temperature rise between the peripheryof the preform and the interior of the preform. The peripheral lowtemperature region of the polymer mechanically stabilizes the preform atdemolding. The mechanical strength of the preform can therefore dependon the temperature gradient during the cooling process. For example, thecooled periphery of the preform (e.g., a cooled outer shell) depend onthe peripheral temperature gradient. The peripheral temperature gradientis mainly a function of the mold surface temperature. A mold utilizing ahigh conductivity alloy and a cooling means, such as cold cooling fluid,can produce a low mold surface temperature, thus a steeper temperaturegradient and therefore a mechanically stable “shell” faster than, e.g.,a steel mold. Thus, the combination of high heat transfer material and alow temperature cooling fluid (e.g., refrigerants including cryogenicfluids) are especially useful for post-cooling processes.

Utilizing a low temperature cooling fluid in combination with a steelmold will only bring moderate success. The poor heat conductivity ofsteel produces a steep temperature gradient in the mold, thereby leadingto a high surface temperature in the mold. Utilizing a high conductivitymold alloy in combination with a non-refrigerant cooling fluid, such aswater, will result in a generally flat temperature gradient in the mold.Additionally, the temperature of the mold surface can be warmer thanmold surfaces cooled with refrigerants. Thus, if a mold utilizes steelor non-refrigerant cooling fluids, the formation of a rigid shell, whichallows early demolding, will be delayed and therefore increase cycletime.

The cavity section 192 comprising the high heat transfer material canprovide high heat transfer rates that may not be achieved withtraditional molds. Traditional molds are typically made of steel that issubjected to high thermal stresses upon rapid and large temperaturechanges. The thermal stresses may cause strain hardening of the steeland may dramatically reduce mold life. For example, cyclic thermalloading can cause fatigue which eventual compromises the structuralintegrity of the molds. Steel and some other typical mold materials maybe unsuitable for the extreme temperature loads and thermal cycles.Thus, these materials may be unsuitable for use with refrigerants, suchas cryogenic fluids. Copper has a high thermal conductivity and canundergo rapid temperature changes. However, copper is a relatively softmaterial that has a relatively low mechanical strength and hardness and,thus, may not be able to withstand high clamp forces experienced duringmolding processes. Also, if copper forms the molding surfaces, thecopper can become worn and roughened after extended use and can resultin improperly formed molded articles. However, some high heat transfermaterials are much more suitable for rapid and large temperature changeswhile also having improved mold life. The high heat transfer materialscan withstand cyclic thermal loading with limited amounts of damage dueto fatigue. The high heat transfer materials can be hardened materialfor an improved life as compared to copper. Advantageously, the highheat transfer material can transfer heat at a higher rate than steel andother traditional mold materials. Thus, cycle times can be reduced dueto the thermal properties of high heat transfer materials.

Additionally, because the fluid in the channels 204 is at such a lowpressure, the channels can be located extremely close to the cavitymolding surface 203. For example, the distance between one or more ofthe channels 204 and the cavity molding surface 203 can be less thenabout 5 cm, 3 cm, 2 cm, 1 cm, and ranges encompassing such distances. Inone embodiment, the distance between one or more of the channels 204 andthe cavity molding surface 203 can be less then about 1.5 cm. In yetanother embodiment, the distance between one or more of the channels 204and the cavity molding surface 203 can be less then about 5 mm. In yetanother embodiment, the distance between one or more of the channels 204and the cavity molding surface 203 can be less then about 3 mm. Thecombination of the high heat transfer materials and the location of thechannels 204 can provide extremely quick temperature changes of thecavity molding surface 203. If high heat transfer material is employedin the mold apparatus 132, the channels 204 can be moved away from thecavity molding surface 203 while still providing effective temperaturecontrol of the surface 203. Other types of temperature control elementsthan channels (e.g., heaters) can be similarly positioned in the moldapparatus 132.

As illustrated in FIG. 10 and FIG. 11 (an elevational partialcross-sectional view of the cavity section 192), the channels 204 aregenerally annular channels, preferably substantially concentric with thecavity molding surface 203 to ensure that the thickness of the portion220 between the cavity molding surface 203 and the channels 204 issubstantially uniform. The heat transfer between the melt and the fluidin the channels can be increased by decreasing the distance between thechannels 204 and the cavity molding surface 203. Those skilled in theart recognize that the channels 204 can have various shapes and sizesdepending on desired heat distributions in the mold apparatus 132. Inthe illustrated embodiment, the channels 204 have a substantiallycircular cross-sectional profile. In other embodiments, the channels 204can have a cross-sectional profile that is generally elliptical,polygonal (including rounded polygonal), or the like. In one embodiment,the cavity section 192 has less than about then about ten channels 204.In another embodiment, the cavity section 192 has less than about sevenchannels 204. In another embodiment, the cavity section 192 has lessthan about four channels 204. The number and placement of channels 204can be selected for efficient cooling of the mold apparatus 132.

With reference to FIG. 11, fluid F flows from the conduit 216 throughthe pressure reducing element 212 and into the channel 204. The fluid F(preferably a two-phase flow) is split into two fluid flows and passesthrough the two semi-circular portions of the channel 204 towards theconduit 240. The fluid F then passes through the conduit 240 to the moldinlet 136 and into the fluid line 140. Heat is transferred between thefluid F in the channels 204 and the mold cavity section 192 because ofthe temperature difference between the fluid F and the walls of thechannels 204. If the working fluid F is a two-phase flow, the liquidcomponent of the flow can undergo a phase change become a gas as thefluid absorbs heat. Advantageously, the temperature of the fluid F canremain generally constant along the channels 204, so long as the fluid Fcomprise liquid.

If the temperature of the channels 204 is at a temperature higher thanthe temperature of the fluid in the channels 204, there will be heattransferred to the fluid F. Thus, the mold apparatus 132 can be cooledas heat is transferred to the fluid F. If the temperature of the fluid Fin the channels 204 is higher than the temperature of the channels 204,heat will be transferred to the channels 204. The flow rate of the fluidF can be increased to increase the heat transfer between the fluid F andthe mold apparatus 132.

With reference again to FIG. 10, the core section 194 has the core 198that is hollow. The core 198 has a wall 244 having a generally uniformthickness proximate to the neck portion 32 of the preform 30. Thethickness of the wall 244 necks down to a distal portion having agenerally uniform thickness. A temperature control arrangement 246 isdisposed in the core 198 and comprises a core channel or tube 248located centrally in the core 298 which preferably receives fluid F fromthe fluid line 130 and delivers fluid F directly to a base end 254 ofthe core 198. The fluid F passes through a pressure reducing element260, preferably an expansion valve, and into a channel 208. In theillustrated embodiment, the channel 208 is defined by the outer surfaceof the core channel 248 and an inner surface 210 of the wall 244 of thecore. The fluid F works its way up the core 198 from the base end 254though the channel 208 and exits through an output line 270. In oneembodiment, the fluid F in the core channel 248 is a liquid that isvaporized as it passes through the pressure reducing element 260. Atleast a substantial portion of the fluid in the channel 208 can be gas,preferably at a lower temperature than the temperature of the fluid inthe core channel 248, to ensure that the core 198 is maintained at asuitable temperature. In some embodiments, the pressure reducing elementis positioned outside of the core 198. Thus, a gas or two-phase flow canbe delivered to the core channel 208.

Different fluids can be used to control the temperature of the cavitysection 192 and the core section 194. In one embodiment, for example,the fluid line 130 can comprise two tubes where one of the tubesdelivers CO₂ to the cavity section 192 and the other tube delivers N₂ tothe core section 194. Thus, the temperature control systems can usemultiple fluids to maintain desirable temperatures in the mold apparatus132. In other embodiments, similar fluids can be used in the cavitysection 192 and the core section 194. For example, CO₂ can be theworking fluid in the cavity section 192 and the core section 194.

Pulse temperature control can be utilized to periodically heat or coolthe mold apparatus 132. In some embodiments, pulse temperature controlcomprises pulse cooling. For pulse cooling, fluid cam be pulsed throughthe mold apparatus 132 for periodic temperature changes. When themoldable material is disposed in the mold apparatus 132, chilled fluidcan circulate through the apparatus 132 to cool the polymer material.During the reduced flow period of pulse cooling, the flow of chilledfluid is substantially reduced or stopped. In one embodiment, the flowregulator 214 is controlled to stop the flow of fluid through the moldapparatus 132. The flow regulator 214 can independently stop or reducethe fluid flow into each of the conduits 216. In another embodiment, thevalve 222 can be operated to stop or reduce the flow of the fluidthrough the mold apparatus 132.

The reduced flow period preferably corresponds to when the moldapparatus 132 is empty and/or during non-use of the mold apparatus 132(e.g., during repair periods). For example, after the preform is at adesired temperature, the core section 194 and the cavity section 192 canbe separated; as shown in FIG. 24, and the preform can be removed fromthe mold apparatus 132. While the core section 194 and cavity section192 are separated, the flow rate of the fluid through the mold apparatus132 is reduced to inhibit the formation of condensation on the surfacesof the mold. The flow of chilled fluid can be reduced before or afterthe core section 194 and the cavity section 192 are separated.

Advantageously, pulse cooling efficiently uses fluid from fluid sourceand can result in reduced cycle time and properly formed preforms. Thetemperature control system may be an open loop with a fluid sourcehaving a limited supply of fluid. The refrigerant is efficiently usedduring manufacturing periods that require heat transfer to therefrigerant, such as for cooling preforms. The frequency of replacingthe fluid source is reduced because fluid is used for cooling thepreform and is not used when, for example, the mold apparatus 132 isempty.

As mentioned above, the pulse cooling can reduce condensation that formson the preform molds during preform production. Condensation can form onthe molding surfaces when moisture in the air contacts the moldsurfaces, which are at a low temperature (i.e., the dew point orcondensation formation temperature). When the temperature of the air islowered to its dew point, condensation can form on the mold surfaces.During the preform manufacturing process, the surfaces of the preformmold may be exposed to the air (e.g., after the preform has been removedfrom the mold but before the mold has been injected with melt).Conventional cooling systems may continuously passing chilled waterthrough the mold causing the temperature of the surfaces of the mold toreach the condensation formation temperature resulting in the formationof condensation. In other words, while the surfaces of the mold areexposed to the air, the continuous cooling of conventional systems maylower the surface temperature of the mold such that moisture from theatmosphere condenses on the surfaces of the mold. This can interferewith the preform manufacturing process. For example, condensation cancontact the injected melt and inhibit the flow of the melt through themold and therefore causes improperly formed preforms.

Advantageously, pulse cooling is used to remove heat from the melt whilelimiting the formation of condensation on the surfaces of the mold. Thereduced flow period of the pulse cooling can correspond to when thesurfaces (e.g., the core surface 201 and the cavity molding surface 203)of the mold apparatus 132 are exposed to the air so that the surfacesare not at sufficiently low temperatures to cause the formation ofcondensation. Thus, the preform can be rapidly cooled thereby reducingthe cycle time without forming condensation on the surfaces of the moldapparatus 132.

The mold apparatus 132 of FIG. 10 can be used to produce preforms havingthin walls with low residual stresses. In one embodiment, the melt canbe injected into the space 200 defined by the uncoated preform and thecavity molding surface 203, which are distanced to form preforms withthin walls. The temperatures of the surfaces 201, 203 are sufficientlyhigh so that the melt injected into the space 200 remains in a liquidstate as it passes along space 200. A reduced flow of the chilled fluidcan ensure that the temperature of the surfaces 201, 203 is sufficientlyhigh for proper flow of the melt. In one embodiment, to ensure that themelt passes easily through the space 200, the surfaces 201, 203 can beheated by a heated flow through the channels 204. After the melt flowsinto the space 200, the flow of fluid can then be reversed to cool themelt. Thus, the temperature control system can facilitate the flow ofthe melt into the mold and then can rapidly cool the melt resulting inreduced cycle times and preforms with low residual stresses.Additionally, the melt can be injected into the mold at a lowerinjection pressure because of the high temperatures of the mold'ssurfaces facilitating spreading of the melt.

With continued reference to FIG. 10, the core 198 can be very slenderwhile providing rapid cooling of the melt. The temperature controlarrangement 246 can be utilized for substantial heat loads even though alow amount of fluid flows through the core 198. Advantageously, the lowvolumetric flow rates allow an increased thickness of the wall 244 toensure that the core 198 is properly aligned with the cavity moldingsurface 203 during the molding process. In some embodiments, a portionof the core 198 for molding the preform has a length equal to or greaterthan about 7 cm, 8 cm, 9 cm 10 cm, 11 cm, 12 cm, 13 cm and an averageouter diameter equal to or less than about 1 cm, 1.5 cm, 2 cm, 2.5 cm.The length and diameter can be selected based on the preform design. Thelength of the core corresponds to the portion of the core that molds theinterior surface of the preform. Thus, the length of the core generallycorresponds to the distance from the opening of the preform to theinterior surface of the preform forming the end cap. The diameter of thecore is the average outer diameter of the portion of the core that formsthe preform. In some embodiments, the core 198 has a length greater thanabout 11 cm and an outer diameter of less than about 2 cm. Preferably,the core 198 has a length to diameter (L/D) ratio equal to or greaterthan about 4, 4.5, 5, 5.5, 5.8, 6, 6.5, 7, 8, 9, 10, 11, 12, 13, andranges encompassing such ratios. In some embodiments, the core 198 hasan L/D ratio greater than about 5. In yet another embodiment, the core198 has an L/D ratio greater than about 7. Thus, the core 198 can have ahigh L/D ratio because of the temperature control arrangement 246 havinghigh heat transfer capabilities.

Due to the thermal capabilities of refrigerants, the channels in thecore 198 can be smaller than water passages in conventional coresfurther allowing higher L/D ratios. Conventional cores may not be rigidenough to form thin walled preforms because of their thin core walls.These conventional cores may move during the molding process resultingin preforms that will likely have weak spots or other defects that couldaffect container performance. Additionally, the pressure reducing device260 can be smaller than many of the conventional valves used in typicalcold-water bubblers.

The thickness of the wall 244 can be increased because of the reducedsize of the channels and valve within the core 198, thereby increasingthe rigidity of the core 198. The increased rigidity of the core 198 canensure that the surface 201 of the core 198 is generally concentric withthe surface 203 of the cavity section 192. The concentric surfacesresult in the production of preforms that have generally uniform wallthicknesses. Thus, the mold apparatus 132 can be used to produce thelong, small diameter articles with thin wall sections that would nototherwise be manufactured by injection molding processes.

With continued reference to FIG. 10, the core section 194 has channels206 that are in fluid communication with the fluid lines 130, 140. Thecore section 194 has channels and valves similar to the cavity section192. The temperature of the core section 194 is maintained in a similarmanner as the cavity section 192 and therefore will not be discussed infurther detail.

The melt, as well as the uncoated preform, is cooled or heated by fluidcirculating in channels 204 and 206 in the two halves of the mold.Preferably the circulation in channels 204 is completely separate fromthe circulation of fluid in the channels 206. Additionally, although notillustrated, cold water-bubblers can be used to cool the core 198illustrated in FIG. 10.

FIG. 12 illustrates a modified injection mold that can be used to make amultilayer preforms. To further reduce condensation on the moldapparatus 132, the temperature control system can have the feedback line232 (see FIG. 9A), which is in fluid communication with the fluid line140 and the mold apparatus. The temperature of the fluid in the fluidline 140 is sufficiently high such that the fluid in the fluid line 140can be used utilized to heat portions of the mold apparatus 132. Thechannels 204 can be used to reduce the temperature of portions of themold apparatus 132 at different rates by passing fluid at differenttemperatures through different channels 204. One or more of the channelscan contain heated fluid while one or more of the channels containcooled fluid. Alternatively, heaters (such as resistance heaters) can beemployed to heat portions of the preform to, e.g., causecrystallization. Thus, the channels and the flow fluid can be used toobtain the desired temperature distributions through the mold apparatus132.

In the illustrated embodiment, heated fluid from the fluid line 140passes through the feedback line 232 and through the upper channel 204while the cooling fluid from the fluid line 130 passes through the otherchannels 204. The temperature of the upper portion of the preform bodyis higher than the temperature of the lower portion of the body portionof the preform. Similarly, although not illustrated, heated fluid fromthe feedback line 232 can pass through one or more of the channels 206while the cooling fluid from the fluid line 130 can pass through theother channels 206.

With reference to FIG. 13, a preferred embodiment of the mold apparatus132 having a mold core 298 and associated mold cavity 300 are shown. Theillustrated mold apparatus 132 is configured to produce a monolayerpreform. Channels 302 are formed just below the surface 304 of the moldcavity 300. The channels 302 can be formed in a spiral fashion or in anyother configuration for permitting flow through the mold apparatus 132.A gate area 306 of the cavity 300 is defined near a gate 308 and aninsert 310 of a material with especially high heat transfer propertiesis disposed in the cavity at the gate area 306. Thus, the injectedpreform's gate area/base end 314 is cooled especially quickly.

The core 298 is hollow and has a wall 320 of generally uniformthickness. The outer surface of the wall 320 can define a core moldingsurface. A temperature control arrangement 330 is disposed in the hollowcore 298 and comprises a core channel or tube 332 located centrally inthe core 298. The pressure reducing element 212 is located at the distalend of the channel 332. Fluid F passes through the pressure reducingelement 212 and is delivered to a base end 322 of the core 298.Preferably, the pressure reducing element 212 provides a pressurereduction such that the fluid F in the channel 332 comprises liquid andthe fluid is delivered by the pressure reducing element 212 to the baseend 322 preferably comprises gas, or a liquid/gas mixture. Since thebase end 322 is the first point of the core 298 contacted by this fluidF, the fluid is coldest and most effective at this location. Thus, thegate area 314 of the injected preform is cooled at a faster rate thanthe rest of the preform. Fluid injected into the core at the base end322 proceeds along the length of the core 298 and exits through anoutput line 334. A plurality of ribs 336 are arranged in a spiralpattern around the core tube 332 to direct fluid F along the core wall.Fluid F works its way up the core from the base end 322 and exitsthrough an output line 334. The core channel 332 is held in place byribs 336 extending between the tube and the core wall 320.

To enhance the cooling effect of the core 298 on the inner surface ofthe preform and especially to enhance the cooling effect of the core 298at the preform's gate area/base end 314, the core 298 is preferablysubstantially hollow, having a relatively thin uniform wall 320.Preferably, this uniform thickness is between 0.254 cm and 0.762 cm (0.1inch and 0.3 inches) and is most preferably about 0.508 cm (0.2 inches).The wall 320 at the base end 322 of the core 298 may by thinner than therest of the core wall 320 because the thin wall aids in rapidlycommunicating heat away from the molten gate area 314 of the injectedpreform.

In other embodiments where greater crystallinity and less crystallinegradient are desired, molds are paired with modified cores. In themodified cores, the fluid circulation in the cores is modified suchthat, for the portions to form the crystalline preform parts, the fluidcirculation is independent and at a relatively higher temperature, orthe flow of chilled fluid is restricted or altered in these regions suchthat the temperature of the surface of the core in the portion whichforms the crystalline portion of the preform is higher than that in thebody regions. Alternatively, the relevant portions of the core may beheated by other means as described above. Use of cores having thesecharacteristics allows for a greater degree of crystallization towardsand/or at the inner surface of the preform in the neck, neck finishand/or neck cylinder area and a lesser crystalline gradient between theinner surface and the outer surface in these areas.

The cavity section 404 has several channels 302 through which a fluid,preferably a chilled gas or liquid/gas mixture, is circulated. Thecavity section 404 can comprise high heat transfer material to increasethermal communication between the melt and channels 302. The cavitysection 404 can comprise a mold plate that comprises high heat transfermaterial.

The neck finish mold 402 of FIG. 13 is configured to form at least aportion of the preform. The neck finish mold 402 can comprise high heattransfer material. For example, the neck finish mold 402 can comprisemore than about 5%, 20%, 50%, 70%, 80%, and 90% and ranges encompassingthese amounts of high heat transfer material by weight. In someembodiments, the neck finish mold 402 comprises mostly or entirely highheat transfer material, such as copper and its alloys (e.g., AMPCOLOY®alloy). The neck finish mold 402 can be formed of more than one material(e.g., bimetallic) or formed of a single material. When high heattransfer material forms the neck finish mold, the melt can be rapidlycooled so that a somewhat stable outer layer is formed on the preform,so that the preform can be ejected from the mold. This outer layereggshell-like layer and may be relatively thin and suitable forpermitting demolding of the preform. Preferably, the preform can beremoved from the mold without damaging the preform, even though theinner portions of the preform may be very soft. The preform can beremoved from the mold when the inner and outer portions are bothrelatively cool. The eggshell-like layer permits design flexibility. Theouter layer functions as a protective layer that allows further coolingof the interior portions of the preform subsequent to demolding. Thepreform can have thick and/or thin neck cylinders because of cooledouter layer and the ease of demolding. Even if the interior portion ofthe neck cylinder comprises a hot, soft polymer, the preform can bedemolded, thereby reducing cycle time.

The neck finish mold 402 can have one or more temperature controlelements 403 for cooling and/or heating the molded material. Theillustrated neck finish mold 402 comprises a plurality of temperaturecontrol elements 403 in the form of channels in which a fluidcirculates. A portion 411 the neck finish mold 402 is positioned betweenthe channels 403. The portion 411 preferably forms at least asubstantial portion of the neck finish mold interposed between theplurality of fluid channels 403 and the mold cavity 300. In someembodiments, the portion 411 preferably comprises high heat transfermaterial for high heat flow through the neck finish mold 402.

The fluid circulation in channels 403, 302 are preferably separate andindependent. The fluid F circulating through the core section 400 isalso separate from both channels 403, 302. However, a fluid source orsingle coolant source may provide the fluid for the core section 400,the channels 302, and/or the channels 302.

Thermal isolation of the cavity section 404, neck finish mold 402 andcore section 400 is achieved by utilizing inserts 406 having low thermalconductivity. However, materials having low thermal conductivity shouldnot be used on the molding surfaces which contact the preform. Examplesof preferred low thermal conductivity materials include heat-treatedtool steel (e.g. P-20, H-13, stainless steel, etc.), polymeric insertsof filled polyamides, nomex, air gaps and minimum contact shut-offsurfaces.

To produce preforms with a crystalline neck finish, the fluid in thechannels 402 can be warmer than the fluid in the portions of the moldused to form non-crystalline portions of the preform. To producepreforms with amorphous neck finishes and body portions, all of thechannels can contain relatively cool fluid. In some embodiments, theportions of the mold which form the crystalline portions of the preform,(corresponding to neck finish mold 402) contain a heating apparatusplaced in the neck, neck finish, and/or neck cylinder portions of themold so as to maintain the higher temperature (slower cooling) needed topromote crystallinity of the material during cooling. Such a heatingapparatus includes but is not limited to heating coils, heating probes,and electric heaters. A feedback system can also deliver heated fluidused to heat portions of the mold to form crystalline material.

FIG. 13A illustrates a neck finish mold 402 a that comprises a firstportion 401 a and a second portion 419 a. The first portion 401 a andthe second portion 419 b can have different thermal conductivities. Insome embodiments, the first portion 401 a has a thermal conductivitygreater, preferably substantially greater, than the second portion 419a. The first portion 401 a preferably comprises a high heat transfermaterial (e.g., a mid or high range high heat transfer material). Thesecond portion 419 a can comprises a low thermally conductive material,such as tool steel. Such a neck finish mold can have one or moretemperature control elements. The illustrated neck finish mold 402 a hasa plurality of temperature control elements in the form of fluidchannels 405 a. Some exemplary embodiments of neck finish molds may havetemperature control systems 405 a that include one or more of thefollowing: channels, heat/cooling rods, bubblers, heaters (e.g.,electric heaters) and combinations thereof. Preferably, the high heattransfer material of the neck finish mold 402 a is proximate to or formsthe molding surface which contacts the melt that is injected into a moldcavity. The illustrated neck finish mold 402 a is configured to moldthreads of a preform, although the neck molding surface can beconfigured to mold other neck finishes.

Optionally, the neck finish mold 402 a can have one or more portions 409that can reduce heat transfer between the neck finish mold 402 a and anadjacent cavity section and/or core section. Thus, thermal isolation ofone or more portions of a preform can be achieved. During operation, thefirst portion 401 a can be at a first temperature and the second portion419 a can be at second temperature. The neck finish mold 402 a may thusselectively control the temperature of the neck of the preform toproduce, e.g., crystalline neck finishes, neck finishes with anegg-shell finish or layer, and the like.

In some embodiments, a portion 399 of the neck finish mold 402 a nearestthe mold cavity has a length L and can comprise more than about 5%, 20%,50%, 70%, 80%, and 90% of high heat transfer material by weight. Thatis, the portion 399 is the portion of the neck molding finish 402 awithin the distance L from the mold cavity. The length L of the portion399 can be less than or equal to about 0.25 inch, 0.5 inch, 1 inch, 1.5inches, and ranges encompassing such lengths. In some embodiments, thelength is greater than or equal to about 1.5 inches, 2 inches, 2.5inches, and ranges encompassing such lengths. In view of the presentdisclosure, a skilled artisan can select the length L suitable forforming the neck finish mold 402 a.

In some embodiments, the neck finish mold 402 a comprises at least 5%,20%, 30%, 50%, 60% 80%, 80%, 90% by weight of high heat transfermaterial. A substantial portion of the neck finish mold 402 a extendingbetween the temperature control element(s) and the neck molding surfacecan comprise high heat transfer material. The high heat transfermaterial preferably forms the neck molding surface for efficient thermalcommunication. The neck molding surface can be configured to form one ormore threads, flanges, recesses, or other structures for engaging aclosure as mentioned above. The illustrated neck finish mold 402 a isdesigned to mold threads of a preform. In some embodiments the neckfinish mold 402 a is configured to mold an outer surface of a preformwithout any closure engaging structures. Threads or other structures canbe added to the preform in a subsequent process. Of course, the neckfinish mold can be a split ring that is movable between a first positionfor molding a portion of a preform and a second position for demoldingthe preform.

FIGS. 13B-13F illustrate neck finish molds that are similar to the neckmold finish 402 a, except as described below. FIG. 13B illustrates aneck finish mold 402 b that has a first portion 401 b that forms anupper surface 413 and lower surface 415 of the neck mold finish 402 b.The first portion 401 b preferably comprises high heat transfermaterial. A temperature control element 405 b in the form of aheating/cooling rod is positioned within the neck finish mold 402 b,preferably positioned within the first portion 401 b. Additionaltemperature control elements (e.g., channels, rods, heaters, etc.) canbe positioned within the first portion 401 b.

With reference to FIG. 13C, a neck finish mold 402 c has a first portion401 c that extends into the second portion 419 c. A temperature controlsystem 405 c can be positioned within the first portion 401 c toeffectively cool the melt, even though the temperature control system405 c may not be proximate to the molding surface 407 c.

With reference to FIG. 13D, the neck finish mold 402 d comprises aplurality of portions 401 d, 410 d′ comprising high heat transfermaterial that have different or similar thermal conductivities. Each ofthe portions 401 d, 401 d′ can have one or more temperature controlelements 405 d. A portion 409 d is positioned between the portions 401d, 401 d′ for thermal isolation of the portions 401 d, 401 d′. Thus, theportions 401 d, 401 d′ can be at the same or different temperatures toprecisely control the temperature of the preform.

FIGS. 13E and 13F illustrated additional embodiments of neck finishmolds having a plurality of temperature control elements. Theillustrated neck finish mold 402 e has a temperature control element 405e in the form of a heating/cooling rod and a channel 405 e′ positionedwithin the portion 401 e. FIG. 13F illustrates a neck finish mold 402 fcomprising a plurality of a heating/cooling rods 405 f and a pluralityof channels 405 f′. As such, the temperature control elements may or maynot be positioned within high heat transfer material. It is contemplatedthat the neck finish molds of FIGS. 13A-13F can be used with the moldingsystems (e.g., the injection and compression molding systems) describedherein. Neck finish molds can thus be bimetallic or formed of a singlematerial. The type and location of materials can be selected to achievethe desired heat flow through the neck finish mold. Various types oftemperature control elements can be used to control the temperature ofthe neck finish molds.

Referring to FIGS. 13, 14, and 15, an air insertion system 340 is shownformed at a joint 342 between members of the mold cavity 300. A notch344 is formed circumferentially around the cavity 300. The notch 344 issufficiently small that substantially no molten plastic will enterduring melt injection. An air line 350 connects the notch 344 to asource of air pressure and a valve regulates the supply of air to thenotch 344. During melt injection, the valve is closed. When injection iscomplete, the valve is opened and pressurized air A is supplied to thenotch 344 in order to defeat a vacuum that may form between an injectedpreform and the cavity wall 304. Additionally, similar air insertionsystems 340 may be utilized in other portions of the mold, such as thethread area, for example but without limitation.

FIG. 16 is a cross-section of an injection mold core having a doublewall neck finish portion. The mold is configured to produce a monolayerpreform that may or may not be overmolded. In some embodiments, the core299 is configured to achieve greater crystallinity of the neck portionof an injected preform. The mold of FIG. 16 is similar in constructionto the mold described above with reference to FIG. 13 and includes acore section 400, the cavity section or body mold 404, and the neckfinish portion 402. The channel or tubes 302, 403 spiral around the core299. The mold cooling system can be optimized for the mold cavities byarranging channels 302 in a spiral arrangement around the mold cavity300 and just below the surface 304.

The core 299 of FIG. 16 includes a double wall portion 408 generallyadjacent to the neck finish portion 402 of the mold. An inner wall 410substantially inhibits circulating fluid F from coming into contact withthe outer wall 412 of the core 299 in the region proximate to the neckfinish portion 402 of the mold. In addition, an insulating space 414 isdefined between the inner wall and the outer wall 412. Accordingly, theinsulating space 414 reduces the cooling effect of the circulating fluidF on the neck portion of a preform within the mold cavity 300, therebyincreasing the crystallinity of the resulting preform and reducing thecrystallinity gradient between the outer surface and the inner surfaceof the resulting preform.

The inner wall 410 of the modified core 299 may optionally include oneor more openings 416. These openings 416 permit circulating fluid F toenter the insulating space 414. Preferably, the size of the openings 416are configured such that a limited amount of circulating fluid F entersthe insulating space 414. Such a construction provides a greater coolingeffect on the neck portion of the resulting preform than when no fluidis permitted within the insulating space 414, but less cooling thanunrestricted contact of the circulating fluid F with the outer wall 412of the core 299. Advantageously, adjustment of the size and placement ofthe openings 416 allows adjustment of the cooling on the neck portion ofthe injected preform, thereby allowing adjustment of the crystallinityand crystallinity gradient in the neck portion.

FIG. 17 is a schematic representation of another embodiment of a core301, including a modified base end 417 or tip. The mold core 301 of FIG.17 is similar in construction to the mold described above with referenceto FIG. 13.

As described above, the end cap portion of the injection molded preformadjacent the base end 417, receives the last portion of the melt streamto be injected into the mold cavity 300. Thus, this portion is the lastto begin cooling. If the PET layer has not sufficiently cooled beforethe overmolding process takes place, the force of the barrier materialmelt entering the mold may wash away some of the PET near the base end417 of the core 301. To speed cooling in the base end 417 of the core inorder to decrease cycle time, the modified core 301 includes a base end442 portion constructed of an especially high heat transfer material,preferably a high heat transfer material, such as AMPCOLOY or othercopper alloy. Advantageously, the AMPCOLOY base end 442 allows thecirculating fluid F to withdraw heat from the injected preform at ahigher rate than the remainder of the core 301. Such a constructionallows the end cap portion of the preform to cool quickly, in order todecrease the necessary cooling time and, thus, reduce the cycle time ofthe initial preform injection.

The modified core 301 illustrated in FIG. 17 generally comprises anupper core portion 418, substantially as illustrated in FIG. 13, and abase end portion 442 constructed of a high heat transfer material,including, but not limited to, a beryllium-free copper alloy, such asAMPCOLOY. A pressure reducing element 430 is at the distal end of thecore channel 332, as described above. That is, the pressure reducingelement 430 can provide a fluid pressure drop. As in FIG. 13, thepresent core channel 332 is operable for delivering circulating coolingfluid F to the base end 442 of the core 301.

The core 301 is substantially hollow and defines an inner diameter D andwall thickness T. The upper core portion 418 includes a recessed step420 having a diameter D_(S) which is greater than the inner diameter Dof the core 301. The upper core portion 418 can be for molding a neckportion of a preform. The base end portion 442 includes a flange 422having a diameter D_(F) which is smaller than the diameter D_(S) of thestep 420. The difference between the diameters D_(S) and D_(F) of thestep 420 and flange 422, respectively, is preferably between about0.0254 mm and 0.635 mm (0.001 and 0.025 inches). More preferably, thedifference is between about 0.254 mm and 0.381 mm (0.010 and 0.015inches). When the base end portion 442 is placed concentrically withinthe upper core portion 418, the difference in the diameters D_(S), D_(F)results in a gap G being formed between the base end and upper coreportions 442, 418. The width W of the gap G is approximately equal toone-half the difference between the diameters D_(S), D_(F).Additionally, the base end portion 442 is preferably about 1.905 cm and3.175 cm (0.750-1.250 inches) in length.

Preferably, the modified core 301 is constructed by starting with anunmodified core 298 made from a single material, substantially asillustrated in FIG. 13. The end portion, or tip, of the unmodified core298 is cut off approximately at the point where the high heat transferbase end 442 is desired to begin. A drilling, or boring, tool may thenbe inserted from the end portion of the core 301 to ensure that theinner diameter D is correctly sized and concentric with a center axis ofthe core 301. This also ensures that the wall thickness T is consistentthroughout the portion of the core 301 which is in contact with theinjected preform, thus ensuring that the cooling of the preform isconsistent as well. Such a method of construction presents a distinctadvantage over conventionally formed cores. In a conventional core,because the length to diameter ratio is large, the drilling tool used tocreate the hollow inner portion of the core often tends to wander, thatis, tends to deflect from the center axis of the core. The wandering ofthe drilling tool results in a core having an inconsistent wallthickness and, thus, inconsistent heat transfer properties. With theabove-described method of sizing the inner diameter D from the base endof the core 301, the problem of tool wandering is substantially reducedor eliminated. Therefore, a consistent wall thickness T and, as aresult, consistent heat transfer properties are achieved.

The upper core portion 418 and base end portion 442 are preferablyjoined by a silver solder process. AMPCOLOY is a preferred material forthe base end portion 442 in part because it contains some silver. Thisallows the silver solder process to provide a joint of sufficientstrength to be useful in injection molding applications. Preferably, thesoldering process results in a full contact joint. That is, soldermaterial is disposed on all of the mating surfaces (424, 426 and gap G)between the upper core portion 418 and base end portion 442.Advantageously, the provision of the gap G enhances the flow of soldermaterial such that a strong joint is achieved. In addition, the fullcontact joint is advantageous because it provides for consistent heattransfer properties and high strength. If the soldered joint was not afull contact joint, any air present in the gap G would result ininconsistent heat transfer through the gap G portion of the core 301.Although it is preferred to join the upper core portion 418 and base endportion 442 with a silver solder process, other suitable joiningprocesses may also be used.

As illustrated in FIG. 17, the base end portion 442 of the modified core301 is preferably of a larger size than the final dimension desired(illustrated by the dashed line 428) when it is joined to the upper coreportion 418. Advantageously, this allows for the base end portion 442 tobe machined to its desired dimension after assembly to the upper coreportion 418 in order to ensure a proper final diameter and a smoothsurface at the transfer from the upper core portion 418 to the base endportion 442.

Another way to enhance cooling of the preform's gate area was discussedabove and involves forming the mold cavity so that the inner polymerlayer (e.g., a PET layer) is thinner at the gate area than at the restof the injected preform as shown in FIG. 4. The thin gate area thuscools quickly to a substantially solid state and can be quickly removedfrom the first mold cavity, inserted into the second mold cavity, andhave a layer of barrier material injected thereover without causingwashing of the PET.

In the continuing effort to reduce cycle time, injected preforms areremoved from mold cavities as quickly as possible. However, it may beappreciated that the newly injected material is not necessarily fullysolidified when the injected preform is removed from the mold cavity.This results in possible problems removing the preform from the cavity300. Friction or even a vacuum between the hot, malleable plastic andthe mold cavity surface 304 can cause resistance resulting in damage tothe injected preform when an attempt is made to remove it from the moldcavity 300 as shown in FIG. 13.

Typically, mold surfaces are polished and extremely smooth in order toobtain a smooth surface of the injected part. However, polished surfacestend to create surface tension along those surfaces. This surfacetension may create friction between the mold and the injected preformwhich may result in possible damage to the injected preform duringremoval from the mold. To reduce surface tension, the mold surfaces arepreferably treated with a very fine sanding device to slightly roughenthe surface of the mold. Preferably the sandpaper has a grit ratingbetween about 400 and 700. More preferably a 600 grit rating sandpaperis used. Also, the mold is preferably sanded in only a longitudinaldirection, further facilitating removal of the injected preform from themold.

While some of the above-described improvements to mold performance arespecific to the method and apparatus described herein, those of skill inthe art will appreciate that these improvements may also be applied inmany different types of plastic injection molding applications andassociated apparatus. For instance, use of high heat transfer materialin a mold may quicken heat removal and dramatically decrease cycle timesfor a variety of mold types and melt materials. Pulse cooling can beused to cool the cores, neck finish portion, and/or the cavity sectionof the mold. Also, roughening of the molding surfaces and provides airpressure supply systems may ease part removal for a variety of moldtypes and melt materials.

FIG. 18 illustrates an injection mold apparatus, similar to thosedescribed above, and referred to generally by the reference numeral 500.The injection mold assembly 500 is configured to produce a monolayerpreform. In the illustrated arrangement, the mold 500 utilizes one ormore hardened materials to define contact surfaces between variouscomponents of the mold 500. As used herein, the term “hardened material”is a broad term and is used in its ordinary sense and refers, withoutlimitation, to any material which is suitable for preventing wear, suchas tool steel. In various embodiments, the hardened or wear resistantmaterial may comprise a heat-treated material, alloyed material,chemically treated material, or any other suitable material. The mold500 also uses one or more materials having high heat transfer propertiesto define at least a portion of the mold cavity surfaces. The mold 500may also utilizes the hardened materials (having generally slower heattransfer properties) to produce a preform having regions with varyingdegrees of crystallinity, similar to the injection molds describedabove. In some embodiments, the molds described herein can comprise ahardened high heat transfer material to reduce wear. For example,hardened copper and its alloys can have a hardness and/or strengthproperties (e.g., yield strength, ultimate tensile strength, and thelike) greater than unhardened pure copper.

As in the mold arrangements described above, the mold assembly 500comprises a core section 502 and a cavity section 504. The core section502 and the cavity section 504 define a parting line P, indicatedgenerally by the dashed line of FIG. 18, between them. The core section502 and the cavity section 504 cooperate to form a mold cavity 506,which is generally shaped in the desired final shape of the preform. Inthe illustrated embodiment, at least a portion of the mold cavity 506 isdefined by a core molding surface 507 and a cavity molding surface 509.The cavity section 504 of the mold 500 can define a passage, or gate508, which communicates with the cavity 506. An injection nozzle 510delivers a molten polymer to the cavity 506 through the gate 508.

Preferably, the core section 502 of the mold 500 includes a core member512 and a core holder 514. The core holder 514 is sized and shaped to beconcentric about, and support a proximal end of, the core member 512.The core member 512 extends from an open end 516 of the core holder 514and extends into the cavity section 504 of the mold to define aninternal surface of the cavity 506 and thus, an internal surface of thefinal preform. The core member 512 and the core holder 514 includecooperating tapered portions 518, 520, respectively, which locate thecore member 512 relative to the core holder 514.

Preferably, the core Member 512 is substantially hollow, thus definingan elongated cavity 522 therein. A core channel or tube 524 extendstoward a distal end of the core cavity 522 to deliver a fluid,preferably a cooling fluid, to the distal end of the cavity 522. As inthe previous arrangements, cooling fluid passes through the core 524 andthrough a pressure reducing element 561, which can be similar topressure reducing element 212, and is delivered to the end of the coremember 512, and progresses through the cavity 522 toward the base of thecore member 512. The pressure reducing element 561 can provide apressure drop in the working fluid similar to pressure reducing element212 for vaporizing at least a portion of the working fluid. A pluralityof tangs 526 extend radially outward from the body of the tube 524 andcontact the inner surface of the cavity 522 to maintain the tube 524 ina coaxial relationship with the core member 512. Such a constructioninhibits vibration of a distal end of the tube 524, thus improving thedimensional stability of the preforms produced by the mold 500.

The cavity section 504 of the mold 500 includes a neck finish mold 528,a main cavity section 530 and a gate portion 532. All of these portions528, 530, 532 cooperate to define an outer surface of the cavity 506,and thus an outer surface of the finished preform produced by the mold500. The distal end of the core member 512 correlates to the distal endof the cavity 506. The neck finish mold 528 is positioned adjacent thecore section 502 of the mold 500 and cooperates with the core section502 to define the parting line P. The neck finish mold 528 defines thethreads 534 and neck ring 536 portions of the cavity 506, and thus ofthe final preform. Preferably, the neck finish mold 528 comprises twosemicircular portions, which cooperate to define the neck finish mold ofthe cavity 506 so that the neck finish mold 528 may be split apart fromone another, in a plane perpendicular to the plane of separation betweenthe core section 502 and cavity section 504, to permit removal of thefinished preform from the cavity 506, as is known in the art.

The main cavity section 530 defines the main body portion of the cavity506. Desirably, the main cavity section 530 also defines a plurality oftemperature control elements in the form of channels 538, which directfluid around the main body portion 530 to maintain the temperature thepreform within the cavity 506. Several conduits 554 receive fluid fromthe fluid line (e.g., the fluid line 130 shown in FIG. 8 and FIG. 9A),and deliver the fluid to the pressure reducing device 558.

The pressure reducing devices are proximate to the high heat transfermaterial portion 530 b. The fluid passes through the pressure reducingdevices 558 and is delivered to the channels 538. As described above,there can be a pressure drop across the pressure reducing devices 558resulting in low temperature fluid, preferably a gas or liquid/gasmixture, in the channels 538. The fluid passes through the channels 538and removes heat from the mold 500 and passes through the conduits 560and into the fluid line 140. In the illustrated embodiment, narrowpassages 562 connect the channels 538. Fluid can pass between thechannels 538 by passing through the passages 562. The channels in themold 500 can be diffusion passages that cause a pressure drop downstreamof the pressure reducing elements 558. The diffusion passages can lowerthe temperature of the working fluid. Although not illustrated, thechannels 538 can spiral around the cavity molding surface 509.

The gate portion 532 of the mold 500 is interposed between the maincavity section 530 and the injection nozzle 510 and defines at least aportion of the gate 508. The gate portion 532 defines one large channel540, but any number of smaller channels may alternatively be provided.Fluid can flow through the channel 540 of the gate portion 532 tomaintain the proper temperature of the gate portion 532. In theillustrated embodiment, the conduit 554 delivers pressurized fluid tothe pressure reducing element 558. The temperature and pressure of thefluid is reduced as it passes through the pressure reducing element 558and into the channel 540. The fluid passes through the channel 540 andheat can be transferred to the fluid. The heated fluid passes out of thechannel 540 and into the conduit 560, which can be connected to thefluid line 140.

A controller can be connected to the valves which feed fluid into thechannels. In one embodiment, a controller 564 is connected to thepressure reducing elements 558 to command one of more of the pressurereducing elements to stop or vary the flow of fluid. The valves 558, forexample, can be controlled to produce pulse cooling for rapid cooling ofthe cavity 506 with minimal formation of condensation on the coresurface 507 and the cavity molding surface 509. In the illustratedembodiment, portions of surfaces 507, 509 formed by high heat transfermaterials can be rapidly cooled, especially after the preform has beenremoved from the cavity 506.

The mold 500 defines a number of contact surfaces defined between thevarious components that make up the mold 500. For example, in theillustrated arrangement, the core section 502, and specifically the coreholder 514 defines a contact surface 542 that cooperates with a contactsurface 544 of the cavity section 504 and, more specifically, the neckfinish mold 528 of the mold 500. Similarly, the opposing side of theneck finish mold 528 defines a contact surface 546 that cooperates witha contact surface 548 of the main cavity section 530.

The corresponding contact surfaces 542, 544 and 546, 548 intersect themold cavity 506 and, therefore, it is desirable to maintain a sufficientseal between the contact surfaces 542, 544 and 546, 548 to inhibitmolten polymer within the cavity 506 from entering between therespective contact surfaces. Preferably, the corresponding contactsurfaces 542, 544 and 546, 548 include mating tapered surfaces,generally referred to as taper locks. Due to the high pressure at whichmolten polymer is introduced into the cavity 506, a large clamp force isutilized to maintain the core section 502 and the cavity section 504 ofthe mold in contact with one another and maintain a good seal betweenthe contact surfaces 542, 544 and 546, 548. As a result of such a highclamp force, it is desirable that the components of the mold 500defining the contact surfaces are formed from a hardened material, suchas tool steel, for example, to prevent excessive wear to these areas andincrease the life of the mold.

Furthermore, as described in detail throughout the present application,it is also desirable that at least a portion of the mold 500 thatdefines the cavity 506 be made of a high heat transfer material, such asAMPCOLOY. Such an arrangement permits rapid heat withdrawal from themolten polymer within the cavity 506, which cools the preform to a solidstate so that the cavity sections 502 and 504 may be separated and thepreform removed from the mold 500. As described above, the rate ofcooling of the preform is related to the cycle time that may be achievedwithout resulting in damage to the preform once it is removed from themold 500.

A decrease in cycle time means that more parts may be produced in agiven amount of time, therefore reducing the overall cost of eachpreform. However, high heat transfer materials that are preferred for atleast portions of the molding surface of the cavity 506 are generallytoo soft to withstand the repeated high clamping pressures that exist atthe contact surfaces 542, 544 and 546, 548, for example. Accordingly, ifan entire mold were to be formed from a high heat transfer material, therelatively short life of such a mold may not justify the decrease incycle time that may be achieved by using such materials. The illustratedmold 500 of FIG. 18, however, is made up of individual componentsstrategically positioned such that the contact surfaces 542, 544 and546, 548 comprise a hardened material, such as tool steel, while atleast a portion of the mold 500 defining the cavity 506 comprises a highheat transfer material, to reduce cycle time.

In the illustrated embodiment, the core holder 514 is desirablyconstructed of a hardened material while the core member 512 isconstructed from a high heat transfer material. Furthermore, the neckfinish mold 528 of the mold desirably is constructed of a hardenedmaterial. The main cavity section 530 preferably includes a hardenedmaterial portion 530 a and a high heat transfer material portion 530 b.The hardened material portion 530 a could be made from the same materialthe neck finish mold 528. The hardened material portion 530 a could bemade from a different material than the neck finish mold 528.Preferably, the hardened material portion 530 a defines the contactsurface 548 while the high heat transfer material portion 530 b definesa significant portion of the mold surface of the cavity 506. The highheat transfer material portion 530 b and the gate portion 532 may bemade from the same or different material. The hardened material portion530 a and the high heat transfer material portion 530 b of the maincavity section 530 may be coupled in any suitable manner, such as asilver soldering process as described above, for example. Furthermore,the gate portion 532 of the mold 500 is also desirably formed from ahigh heat transfer material, similar to the molds described above.

In some embodiments, the neck finish mold 528 may or may not comprisehigh heat transfer material. The illustrated neck finish mold 528comprises a contact portion 802 coupled to an optional insert 801(preferably a threaded insert configured to mold threads of a preform),which preferably comprises high heat transfer material. The contactportion 802 is positioned adjacent the core section 502 of the mold 500and cooperates with the core section 502 to define the parting line P.Preferably, the contact portion 802 is made from a hardened material,such as tool steel. The threaded insert 801 can define the threads 534and the neck ring 536 portion of the cavity 506. The threaded inserts801 can be coupled to the contact portion 802 and can be formed from ahigh heat transfer material. Of course, the threaded insert 801 and thecontact portion 802 can form a portion of the threads 534 and/or neckring 536 and the proximal end of the cavity 506.

With a construction as described above, advantageously the mold 500includes hardened materials at the contact surfaces 542, 544 and 546,548 to provide a long life to the mold 500. In addition, the mold 500also includes high heat transfer materials defining at least a portionof the molding surfaces of the cavity 506 such that cycle times may bereduced and, therefore, through-put of the mold 500 is increased. Suchan arrangement is especially advantageous in molds designed to formpreforms, which are later blow molded into a desired final shape.

Another benefit of the mold 500 is that the hardened material neckfinish mold 528 has a lower rate of heat transfer than the high heattransfer portions of the mold 500. Accordingly, the neck finish of thepreform may become semi-crystalline or crystalline, which allows theneck finish to retain its formed dimensions during a hot-fill process.Furthermore, the portion of the core member 512 adjacent the neck finishmold 528 is preferably high heat transfer material, which rapidly coolsthe inner surface of the thread finish of the preform, thereby allowingthe preform to maintain its formed dimensions when removed from the moldin a less than fully cooled state. The cycle time may be reduced by15%-30% utilizing a mold construction such as mold 500 in comparisonwith a mold made from conventional materials and constructiontechniques. In addition, certain portions of the mold 500 may bereplaced, without necessitating replacement of the entire mold section.For example, the core member 512 and core holder 514 may be replacedindependently of one another. In the illustrated embodiment, the valves558 can be easily replaced by removing the portions of the mold 500.After portions of the mold 500 are removed, the valves 558 are exposedfor convenient valve replacement. For example, the portion 530 b can beremoved from the mold apparatus 132 so that the pressure reducingelement 558 is exposed for rapid replacement. Preferably, the pressurereducing elements 558 are expansion valves that can be inserted into themold 500. Valves with different diameter orifices can be easily andrapidly replaced to produce various preforms comprising differentmaterials. However, in other embodiments the pressure reducing elements558 are built in the mold 500.

The mold 500 can be thermally insulated to reduce heat losses. Theillustrated mold 500 can include a portion 577 comprising a lowthermally conductivity material (e.g., tool steel) that surrounds thechannels 538. The portion 577 can be a thermal barrier that reduces heattransfer between the mold 500 and the surrounding environment. Theportion 577 can be a mold plate that holds various components of themold. The portion 579 of the core section 502 can likewise comprise lowthermally conductivity material to reduce thermal inefficiencies.

FIG. 18A illustrates a modified mold similar to the mold 500 of FIG. 18.The neck finish mold 528 a of FIG. 18A comprises one or more temperaturecontrol elements. The illustrated neck finish mold 528 a comprises apair of temperature control elements 578 in the form of heating/coolingrods. The temperature control elements 578 can be spaced from themolding surface 580 by a distance of about 2 cm, 5 cm, 10 cm, 15 cm, 20cm, 25 cm, 30 cm, 50 cm, and ranges encompassing such distances. Thetemperature control elements 578 can be in the form of channels,bubblers, and other devices to control the temperature of the neckfinish mold 528 a. Any number of temperature control elements can bespaced about the cavity 506. Of course, cooling channels or othertemperature control elements, such as resistance heaters, can also bedisposed in the neck finish mold 528 a.

FIGS. 19 and 20 are a schematic of a portion of the preferred type ofapparatus to make coated preforms in accordance with a preferredembodiment. The apparatus is an injection molding system designed tomake one or more uncoated preforms and subsequently coat the newly-madepreforms by over-injection of a material. FIGS. 19 and 20 illustrate thetwo halves of the mold portion of the apparatus which will be inopposition in the molding machine. The alignment pegs 610 in FIG. 19 fitinto their corresponding receptacles 612 in the other half of the mold.

The mold half depicted in FIG. 20 has several pairs of mold cavities,each cavity being similar to the mold cavity depicted in FIG. 13. Themold cavities are of two types: first injection preform molding cavities614 and second injection preform coating cavities 620. The two types ofcavities are equal in number and are preferably arranged so that allcavities of one type are on the same side of the injection block 624 asbisected by the line between the alignment peg receptacles 612. Thisway, every preform molding cavity 614 is 180° away from a preformcoating cavity 620.

The mold half depicted in FIG. 19 has several cores, such as core 198,one for each mold cavity (614 and 620). When the two halves which areFIGS. 19 and 20 are put together, a core 198 (which can be similar tothe core 298 of FIG. 13) fits inside each cavity and serves as the moldfor the interior of the preform for the preform molding cavities 614 andas a centering device for the uncoated preforms in preform coatingcavities 620. The cores 198 are mounted on a turntable 630 which rotates180° about its center so that a core 198 originally aligned with apreform molding cavity 614 will, after rotation, be aligned with apreform coating cavity 620, and vice-versa. As described in greaterdetail below, this type of setup allows a preform to be molded and thencoated in a two-step process using the same piece of equipment.

It should be noted that the drawings in FIGS. 19 and 20 are merelyillustrative. For instance, the drawings depict an apparatus havingthree molding cavities 614 and three coating cavities 620 (a 3/3 cavitymachine). However, the machines may have any number of cavities, as longas there are equal numbers of molding and coating cavities, for example12/12, 24/24, 48/48 and the like. The cavities may be arranged in anysuitable manner. These and other minor alterations are contemplated aspart of this disclosure.

The two mold halves depicted in FIGS. 21 and 22 illustrate an embodimentof a mold of a 48/48 cavity machine as discussed for FIGS. 19 and 20.Referring to FIG. 23 there is shown a perspective view of a mold of thetype for an overmolding (inject-over-inject) process in which the cores,such as cores 198, are partially located within the cavities 614 and620. The arrow shows the movement of the movable mold half 642, on whichthe cores 198 lie, as the mold closes.

FIG. 24 shows a perspective view of a mold of the type used in anovermolding process, wherein the cores 198 are fully withdrawn from thecavities 614 and 620. When the cores 198 are fully withdrawn from thecavities 614, 620, the moisture in the air may form condensation on eachcavity if the temperature of the surface of the cavity is sufficientlylow. The arrow indicates that the turntable 630 rotates 180° to move thecores 198 from one cavity to the next. In the illustrated embodiment,the fluid lines 130 and 140 rotate with the turntable 630. On thestationary half 644, the cooling for the preform molding cavity 614 isseparate from the cooling for the preform coating cavity 620. The fluidline 130 connected to the turntable 630 and the fluid line 130 connectedto the stationary half 644 can be connected to the same fluid source ordifferent fluid sources. Thus, the stationary half 644 and the turntable630 can have independent temperature control systems, such as thetemperature control system 120. The cooling of the cavities of thestationary half 644 is separate from the cooling for the cores 198 inthe movable half.

The preferred method and apparatus for making multilayer preforms isdiscussed in more detail below. Because the methods and apparatus areespecially preferred for use in forming multilayer bottles comprisingcertain preferred materials, the physical characteristics,identification, preparation and enhancement of the preferred materialsis discussed prior to the preferred methods and apparatus for workingwith the materials.

1. Preferred Overmolding (Inject-Over-Inject) Processes

The overmolding is preferably carried out by using an injection moldingprocess using equipment similar to that used to form the uncoatedpreform itself. A preferred mold for overmolding, with an uncoatedpreform in place is shown in FIG. 10. The mold comprises two halves, acavity section 192 and a core section 194, and is shown in FIG. 10 inthe closed position prior to overinjecting. The cavity section 192comprises a cavity in which the uncoated preform is placed. The supportring 38 of the preform rests on a ledge 196 and is held in place by thecore section 194, which exerts pressure on the support ring 38, thussealing the neck portion off from the body portion of the preform. Thecavity section 192 has a plurality of tubes or channels 204 thereinwhich carry a fluid as discussed above. Preferably the fluid in thechannels circulates in a path in which the fluid passes into the cavitysection 192, through the channels 204, and out of the cavity section192. In a closed loop system, the fluid is passed back into the cavitysection 192 after the fluid reaches a desired temperature. Thecirculating fluid serves to cool the mold, which in turn cools theplastic melt which is injected into the mold to form coated or uncoatedpreforms. Of course, the fluid can flow through an open loop system, asdescribed above.

The core section 194 of the mold comprises the core 198. The core 198,sometimes called a mandrel, protrudes from the core section 194 of themold and occupies the central cavity of the preform. In addition tohelping to center the preform in the mold, the core 198 cools theinterior of the preform. The cooling is done by fluid circulatingthrough channels in the core section 194 of the mold, most importantlythrough the length of the core 198 itself. The channels 206 of the coresection 194 work in a manner similar to the channels 204 in the cavitysection 192, in that they create the portion of the path through whichthe cooling fluid travels which lies in the interior of the mold half.

As the preform sits in the mold cavity, the body portion of the preformis centered within the cavity and is completely surrounded by a voidspace 200. The preform, thus positioned, acts as an interior die core inthe subsequent injection procedure. The melt of the overmoldingmaterial, preferably, comprising a barrier material, is then introducedinto the mold cavity from the injector via gate 202 and flows around thepreform, preferably surrounding at least the body portion 34 of thepreform. Following overinjection, the overmolded layer will take theapproximate size and shape of the void space 200.

To carry out the overmolding procedure, one preferably heats the initialpreform which is to be coated preferably to a temperature above its Tg.In the case of PET, that temperature is preferably about 60 to 175° C.,more preferably about 80-110° C. If a temperature at or above theminimum temperature of crystallization for PET is used, which is about120° C., care should be taken when cooling the PET in the preform. Thecooling should be sufficient to minimize crystallization of the PET inthe preform so that the PET is in the preferred semi-crystalline state.Advantageously, the neck portion of the preform is not in contact withthe melt of overriding material, and thus retains its crystallinestructure. Alternatively, the initial preform used may be one which hasbeen very recently injection molded and not fully cooled, as to be at anelevated temperature as is preferred for the overmolding process.

The coating material is heated to form a melt of a viscosity compatiblewith use in an injection molding apparatus. The temperature for this,the inject temperature, will differ among materials, as melting rangesin polymers and viscosities of melts may vary due to the history,chemical character, molecular weight, degree of branching and othercharacteristics of a material. For the preferred barrier materialsdisclosed above, the inject temperature is preferably in the range ofabout 160-325° C., more preferably 200 to 275° C. For example, for theCopolyester Barrier Material B-010, the preferred temperature is around210° C., whereas for the PHAE XU-19040.00L, BLOX 0005 or BLOX 0003 thepreferred temperature is in the range of 160-260° C., and is morepreferably about 175-240° C. Most preferably, the PHAE injecttemperature is about 175-200° C. If recycled PET is used, the injecttemperature is preferably 250-320° C. The coating material is theninjected into the mold in a volume sufficient to fill the void space200.

The coated preform is preferably cooled at least to the point where itcan be displaced from the mold or handled without being damaged, andremoved from the mold where further cooling may take place. If PET isused, and the preform has been heated to a temperature near or above thetemperature of crystallization for PET, the cooling should be fairlyrapid and sufficient to ensure that the PET is primarily in thesemi-crystalline state when the preform is fully cooled. As a result ofthis process, a strong and effective bonding takes place between theinitial preform and the subsequently applied coating material.

Overmolding can be also used to create coated preforms with three ormore layers. In FIG. 5, there is shown a three-layer embodiment of apreform 72 in accordance with one preferred embodiment. The preformshown therein has two coating layers, a middle layer 74 and an outerlayer 76. The relative thickness of the layers shown in FIG. 5 may bevaried to suit a particular combination of layer materials or to allowfor the making of different sized bottles. As will be understood by oneskilled in the art, a procedure analogous to that disclosed above wouldbe followed, except that the initial preform would be one which hadalready been coated, as by one of the methods for making coated preformsdescribed herein, including overmolding.

-   -   a. A Preferred Method and Apparatus for Overmolding

A preferred apparatus for performing the overmolding process is basedupon the use of a 330-330-200 machine by Engel (Austria). The preferredmold portion the machine is shown schematically in FIGS. 19-24 andcomprises a movable half 642 and a stationary half 644. In one preferredembodiment, both halves are preferably made from hard metal. Thestationary half 644 comprises at least two mold sections 146, 148,wherein each mold section comprises N(N>0) identical mold cavities 614,620, an input and output for cooling fluid, channels allowing forcirculation of cooling fluid within the mold section, injectionapparatus, and hot runners channeling the molten material from theinjection apparatus to the gate of each mold cavity. Because each moldsection forms a distinct preform layer, and each preform layer ispreferably made of a different material, each mold section is separatelycontrolled to accommodate the potentially different conditions requiredfor each material and layer. The injector associated with a particularmold section injects a molten material, at a temperature suitable forthat particular material, through that mold section's hot runners andgates and into the mold cavities. The mold section's own input andoutput for cooling fluid allow for changing the temperature of the moldsection to accommodate the characteristics of the particular materialinjected into a mold section. Different cooling fluids can be used indifferent channels within the mold for proper temperature distributions.Further, although not illustrated, the distance between the cavity moldsurface and the each of the channels can be different. Similarly, thedistance between the cavity mold surface and the valves (e.g., pressurereducing elements) can be different. Consequently, each mold section mayhave a different injection temperature, mold temperature, pressure,injection volume, cooling fluid temperature, etc. to accommodate thematerial and operational requirements of a particular preform layer.

The movable half 642 of the mold comprises a turntable 630 and aplurality of cores 198. The alignment pins guide the movable half 642 toslidably move in a preferably horizontal direction towards or away fromthe stationary half 644. The turntable 630 may rotate in either aclockwise or counterclockwise direction, and is mounted onto the movablehalf 642. The plurality of cores 198 are affixed onto the turntable 630.These cores 198 serve as the mold form for the interior of the preform,as well as serving as a carrier and cooling device for the preformduring the molding operation. The cooling system in the cores isseparate from the cooling system in the mold sections.

The mold temperature or cooling for the mold is controlled bycirculating fluid. The flow rate of fluid can be varied depending on thestage of the preform production. There is separate cooling fluidcirculation for the movable half 642 and for the overmolding section 648of the stationary half 644. Additionally, the initial preform moldsection 646 of the stationary half 644 comprises two separate coolingfluid circulation systems; one for the non-crystalline regions and onefor the crystalline regions. Each cooling fluid circulation set up worksin a similar manner. The fluid enters the mold, flows through a networkof channels or tubes inside as discussed above, and then exits throughan output (e.g., mold inlet 136). From the output, the fluid travelsthrough a temperature control system before going back into the mold. Inanother embodiment, the fluid exits out the temperature control systemby passing out of an exhaust system.

In a preferred embodiment, the cores and cavities are constructed of ahigh heat transfer material, such a beryllium, which is coated with ahard metal, such as tin or chrome. The hard coating keeps the berylliumfrom direct contact with the preform, as well as acting as a release forejection and providing a hard surface for long life. The high heattransfer material allows for more efficient cooling, and thus assists inachieving lower cycle times. The high heat transfer material may bedisposed over the entire area of each core and/or cavity, or it may beonly on portions thereof. Preferably, at least the tips of the corescomprise high heat transfer material. In some embodiments, the high heattransfer material is AMPCOLOY, which is commercially available fromUudenholm, Inc. The temperature control system can employ pulse coolingto cool the cavity and/or core while limiting the formation ofcondensation on the surfaces of the high heat transfer material.

The number of cores is equal to the total number of cavities, and thearrangement of the core 198 on the movable half 642 mirrors thearrangement of the cavities 614, 620 on the stationary half 644. Toclose the mold, the movable half 642 moves towards the stationary half644, mating the core 198 with the cavities 614, 620. To open the mold,the movable half 642 moves away from the stationary half 644 such thatthe cores 198 are well clear of the block on the stationary half 644.After the cores are fully withdrawn from the mold sections 646, 648, theturntable 630 of the movable half 642 rotates the cores 198 intoalignment with a different mold section. Thus, the movable half rotates360°/(number of mold sections in the stationary half) degrees after eachwithdrawal of the cores from the stationary half. When the machine is inoperation, during the withdrawal and rotation steps, there will bepreforms present on some or all of the cores.

The size of the cavities in a given mold section 646, 648 will beidentical; however the size of the cavities will differ among the moldsections. The cavities in which the uncoated preforms are first molded,the preform molding cavities 614, are smallest in size. The size of thecavities 620 in the mold section 648 in which the first coating step isperformed are larger than the preform molding cavities 614, in order toaccommodate the uncoated preform and still provide space for the coatingmaterial to be injected to form the overmolded coating. The cavities ineach subsequent mold section wherein additional overmolding steps areperformed will be increasingly larger in size to accommodate the preformas it gets larger with each coating step.

After a set of preforms has been molded and overmolded to completion, aseries of ejectors eject the finished preforms off of the cores 198. Theejectors for the cores operate independently, or at least there is asingle ejector for a set of cores equal in number and configuration to asingle mold section, so that only the completed preforms are ejected.Uncoated or incompletely-coated preforms remain on the cores so thatthey may continue in the cycle to the next mold section. The ejectionmay cause the preforms to completely separate from the cores and fallinto a bin or onto a conveyor. Alternatively, the preforms may remain onthe cores after ejection, after which a robotic arm or other suchapparatus grasps a preform or group of preforms for removal to a bin,conveyor, or other desired location.

FIGS. 19 and 20 illustrate a schematic for an embodiment of theapparatus described above. FIG. 20 is the stationary half 644 of themold. In this embodiment, the block 624 has two mold sections, onesection 646 comprising a set of three preform molding cavities 614 andthe other section 648 comprising a set of three preform coating cavities620. Each of the preform coating cavities 620 is preferably like thatshown in FIG. 10, discussed above. Each of the preform molding cavities614 is preferably similar to that shown in FIG. 13, in that the materialis injected into a space defined by the core 198 (albeit without apreform already thereon) and the wall of the mold which is cooled byfluid circulating through channels inside the mold block. Consequently,one full production cycle of this apparatus will yield three two-layerpreforms. If more than three preforms per cycle is desired, thestationary half can be reconfigured to accommodate more cavities in eachof the mold sections. An example of this is seen in FIG. 22, whereinthere is shown a stationary half of a mold comprising two mold sections,one 646 comprising forty-eight preform molding cavities 614 and theother 648 comprising forty-eight preform coating cavities 620. If athree or more layer preform is desired, the stationary half 644 can bereconfigured to accommodate additional mold sections, one for eachpreform layer

FIG. 19 illustrates the movable half 642 of the mold. The movable halfcomprises six identical cores 198 mounted on the turntable 630. Eachcore 198 corresponds to a cavity on the stationary half 644 of the mold.The movable half also comprises alignment pegs 610, which correspond tothe receptacles 612 on the stationary half 644. When the movable half642 of the mold moves to close the mold, the alignment pegs 610 aremated with their corresponding receptacles 612 such that the moldingcavities 614 and the coating cavities 620 align with the cores 198.After alignment and closure, half of the cores 198 are centered withinpreform molding cavities 614 and the other half of the cores 198 arecentered within preform coating cavities 620.

The configuration of the cavities, cores, and alignment pegs andreceptacles must all have sufficient symmetry such that after the moldis separated and rotated the proper number of degrees, all of the coresline up with cavities and all alignment pegs line up with receptacles.Moreover, each core must be in a cavity in a different mold section thanit was in prior to rotation in order to achieve the orderly process ofmolding and overmolding in an identical fashion for each preform made inthe machine.

Two views of the two mold halves together are shown in FIGS. 23 and 24.In FIG. 23, the movable half 642 is moving towards the stationary half644, as indicated by the arrow. Two cores 198, mounted on the turntable630, are beginning to enter cavities, one enters a molding cavity 614and the other is entering a coating cavity 620 mounted in the block 624.In FIG. 24, the cores 198 are fully withdrawn from the cavities on thestationary side. The preform molding cavity 614 has two coolingcirculation systems which are separate from the cooling circulation forthe preform coating cavity 620, which comprises the other mold section648. The two cores 198 are cooled by a single system that links all thecores together. The arrow in FIG. 12 shows the rotation of the turntable630. The turntable 630 could also rotate clockwise. Not shown are coatedand uncoated preforms which would be on the cores if the machine were inoperation. The alignment pegs and receptacles have also been left outfor the sake of clarity.

The operation of the overmolding apparatus will be discussed in terms ofthe preferred two mold section apparatus for making a two-layer preform.The mold is closed by moving the movable half 642 towards the stationaryhalf 644 until they are in contact. A first injection apparatus injectsa melt of first material into the first mold section 146, through thehot runners and into the preform molding cavities 614 via theirrespective gates to form the uncoated preforms each of which become theinner layer of a coated preform. The first material fills the voidbetween the preform molding cavities 614 and the cores 198.Simultaneously, a second injection apparatus injects a melt of secondmaterial into the second mold section 648 of the stationary half 644,through the hot runners and into each preform coating cavity 620 viatheir respective gates, such that the second material fills the void(200 in FIG. 20) between the wall of the coating cavity 620 and theuncoated preform mounted on the core 198 therein.

During this entire process, cooling fluid is circulating through thefour separate areas, corresponding to the non-crystalline regions ofmold section 646 of the preform molding cavities 614, the crystallineregions of mold section 646 of the preform molding cavities 614, moldsection 648 of the preform coating cavities 620, and the movable half642 of the mold, respectively. Thus, the melts and preforms are beingcooled in the center by the circulation in the movable half that goesthrough the interior of the cores, as well as on the outside by thecirculation in each of the cavities.

The movable half 642 then slides back to separate the two mold halvesand open the mold until all of the cores 198 having preforms thereon arecompletely withdrawn from the preform molding cavities 614 and preformcoating cavities 620. The ejectors eject the coated, finished preformsoff of the cores 198 which were just removed from the preform coatingcavities. As discussed above, the ejection may cause the preforms tocompletely separate from the cores and fall into a bin or onto aconveyor, or if the preforms remain on the cores after ejection, arobotic arm or other apparatus may grasp a preform or group of preformsfor removal to a bin, conveyor, or other desired location. The turntable630 then rotates 180° so that each core 198 having an uncoated preformthereon is positioned over a preform coating cavity 620, and each corefrom which a coated preform was just ejected is positioned over apreform molding cavity 614. Rotation of the turntable 630 may occur asquickly as 0.5-0.9 seconds. Using the alignment pegs 610, the moldhalves again align and close, and the first injector injects the firstmaterial into the preform molding cavity 614 while the second injectorinjects a second material into the preform coating cavity 620.

A production cycle of closing the mold, injecting the melts, opening themold, ejecting finished multilayer preforms, rotating the turntable, andclosing the mold is repeated, so that preforms are continuously beingmolded and overmolded.

When the apparatus first begins running, during the initial cycle, nopreforms are yet in the preform coating cavities 620. Therefore, theoperator should either prevent the second injector from injecting thesecond material into the second mold section during the first injection,or allow the second material to be injected and eject and then discardthe resulting single layer preform comprised solely of the secondmaterial. After this start-up step, the operator may either manuallycontrol the operations or program the desired parameters such that theprocess is automatically controlled.

Two layer preforms may be made using the first preferred overmoldingapparatus described above. In one preferred embodiment, the two layerpreform comprises an inner layer comprising polyester and an outer layercomprising a barrier material, foam, polyester, and other materialsdisclosed herein. In especially preferred embodiments, the inner layercomprises virgin PET. The description hereunder is directed toward theespecially preferred embodiments of two layer preforms comprising aninner layer of virgin PET, in which the neck portion is generallycrystalline and the body portion is generally non-crystalline. Thedescription is directed toward describing the formation of a single setof coated preforms 60 of the type seen in FIG. 4, that is, following aset of preforms through the process of molding, overmolding andejection, rather than describing the operation of the apparatus as awhole. The process described is directed toward preforms having a totalthickness in the wall portion 66 of about 3 mm, comprising about 2 mm ofvirgin PET and about 1 mm of barrier material. The thickness of the twolayers will vary in other portions of the preform 60, as shown in FIG.4.

It will be apparent to one skilled in the art that some of theparameters detailed below will differ if other embodiments of preformsare used. For example, the amount of time which the mold stays closedwill vary depending upon the wall thickness of the preforms. However,given the disclosure below for this preferred embodiment and theremainder of the disclosure herein, one skilled in the art would be ableto determine appropriate parameters for other preform embodiments.

The apparatus described above is set up so that the injector supplyingthe mold section 646 containing the preform molding cavities 614 is fedwith virgin PET and that the injector supplying the mold section 648containing the preform coating cavities 620 is fed with a barriermaterial.

The movable half 642 of the mold is moved so that the mold is closed. Amelt of virgin PET is injected through the back of the block 624 andinto each preform molding cavity 614 to form an uncoated preform 30which becomes the inner layer of the coated preform. The injectiontemperature of the PET melt is preferably 250 to 320° C., morepreferably 255 to 280° C. The mold is kept closed for preferably 1 to 10seconds, more preferably 2 to 6 seconds while the PET melt stream isinjected and then cooled by the coolant circulating in the mold.

In the first step, the PET substrate is injection molded by injectingmolten PET into the cavities formed by the molds and cores in the moldstack. When the cavity is filled, the resin in the body portion willcome into contact with cooling surfaces and the resin in the neck finishwill come into contact with the heated thread mold. As the PET in theneck finish cools, it will begin to crystallize as a result of thiscontact with the relatively hot mold. Once in contact, thecrystallization will start and continue at a rate determined by time andtemperature. When the neck finish portions of the molds are kept abovethe minimum temperature of crystallization of the PET used,crystallization will begin on contact. Higher temperatures will increasethe rate of crystallization and decrease the time required to reach theoptimum level of crystallization while maintaining post mold dimensionalstability of the neck finish of the preform. At the same time the resinin the neck finish portion is cooling into a crystallized state, theresin in the body portion or lower body portion of the preform will bein contact with the chilled portions of the mold and thus cooled into anamorphous or semi-crystalline state.

The movable half 642 of the mold is then moved so that the two halves ofthe mold are separated at or past the point where the newly moldedpreforms, which remain on the cores 198, are clear of the stationaryside 644 of the mold. When the cores 198 are clear of the stationaryside 644 of the mold, the turntable 630 then rotates 180° so that eachcore 198 having a molded preform thereon is positioned over a preformcoating cavity 620. Thus positioned, each of the other core 198 which donot have molded preforms thereon, are each positioned over a preformmolding cavity 614. The mold is again closed. Preferably the timebetween removal from the preform molding cavity 614 to insertion intothe preform coating cavity 620 is 1 to 10 seconds, and more preferably 1to 3 seconds.

When the molded preforms are first placed into preform coating cavities620, the exterior surfaces of the body portions of the preforms are notin contact with a mold surface. Thus, the exterior skin of the bodyportion is still softened and hot as described above because the contactcooling is only from the core inside. The high temperature of theexterior surface of the uncoated preform (which forms the inner layer ofthe coated preform) aids in promoting adhesion between the PET andbarrier layers in the finished coated preform. It is postulated that thesurfaces of the materials are more reactive when hot, and thus chemicalinteractions between the barrier material and the virgin PET will beenhanced by the high temperatures. Barrier material will coat and adhereto a preform with a cold surface, and thus the operation may beperformed using a cold initial uncoated preform, but the adhesion ismarkedly better when the overmolding process is done at an elevatedtemperature, as occurs immediately following the molding of the uncoatedpreform. As discussed earlier, the neck portion of the preform hasdesirably crystallized from the separated, thermally isolated coolingfluid systems in the preform molding cavity. Since the coating operationdoes not place material on the neck portion, its crystalline structureis substantially undisturbed. However, the neck portion of the preformcan also be amorphous or partially crystalline as desired. In someembodiments, the preform may have a hardened or egg-shell outer layerthat surrounds a soft interior of the preform. The overmolding materialcan be selected to achieve the desired interaction between substrate andthe overmolded layer.

A second injection operation then follows in which a melt of a material(e.g., a barrier melt, recycled melt, polypropylene melt, foam melt,etc.) is injected into each preform coating cavity 620 to coat thepreforms. The temperature of the melt of polymer material is preferably160 to 325° C. The exact temperature range for any individual barriermaterial is dependent upon the specific characteristics of thatmaterial, but it is well within the abilities of one skilled in the artto determine a suitable range by routine experimentation given thedisclosure herein. For example, if BLOX 0005 or BLOX 0003 is used, thetemperature of the melt (inject temperature) is preferably 160 to 260°C., more preferably 200 to 240° C., and most preferably 175 to 200° C.If the Copolyester Barrier Material B-010 is used, the injectiontemperature is preferably 160 to 260° C., more preferably 190 to 250° C.During the same time that this set of preforms are being overmolded withpolymer material in the preform coating cavities 620, another set ofuncoated preforms is being molded in the preform molding cavities 614 asdescribed above.

The two halves of the mold are again separated preferably 3 to 10seconds, more preferably 4 to 6 seconds following the initiation of theinjection step. The preforms which have just been coated in the preformcoating cavities 620, are ejected from the cores 198. The uncoatedpreforms which were just molded in preform molding cavities 614 remainon their cores 198. The turntable 630 is then rotated 180° so that eachcore having an uncoated preform thereon is positioned over a coatingcavity 620 and each core 98 from which a coated preform was just removedis positioned over a molding cavity 614.

The cycle of closing the mold, injecting the materials, opening themold, ejecting finished preforms, rotating the turntable, and closingthe mold is repeated, so that preforms are continuously being molded andovermolded. Those of skill in the art will appreciate that dry cycletime of the apparatus may increase the overall production cycle time formolding a complete preform.

The process using modified molds and chilled cores will produce a uniquecombination of amorphous/crystalline properties. As the core is chilledand the thread mold is heated, the thermal transfer properties of thePET act as a barrier to heat exchange. The heated thread moldscrystallize the PET at the surface of the thread finish, and the PETmaterial transitions into an amorphous form near the core as thetemperature of the PET reduces closer to the core. This variation of thematerial from the inner (core) portion to the outer (thread) portion isalso referred to herein as the crystallinity gradient.

The core temperature and the rate of crystallization of the resin play apart in determining the depth of crystallized resin. In addition, theamorphous inner surface of the neck finish stabilizes the post molddimensions allowing closer molding tolerances than other crystallizingprocesses. On the other side, the crystallized outer surface supportsthe amorphous structure during high temperature filling of thecontainer. Physical properties are also enhanced (e.g. brittleness,impact etc.) as a result of this unique crystalline/amorphous structure.

The optimum temperature for crystallization may vary depending uponfactors including resin grade, resin crystallization temperature,intrinsic viscosity, wall thickness, exposure time, mold temperature.Preferred resins include PET homopolymer and copolymers (including butnot limited to high-IPA PET, Copolyester Barrier Materials, andcopolymers of PET and polyamides) and PEN. Such resins preferably havelow intrinsic viscosities and moderate melt temperatures, preferably IVsof about 74 is 86, and melt temperatures of about 220-300° C. Thepreferred mold temperature range for PET is from about 240-280° C., withthe maximum crystallization rate occurring at about 180° C., dependingupon the above factors, the preferred exposure time range is from about20 to 60 seconds overall, which includes both injection steps ininject-over-inject embodiments, and the preferred injection cavitypressure range is about 5000 to 22000 PSI. Thicker finish wall thicknesswill require more time to achieve a particular degree of crystallinityas compared to that needed for a thinner wall thickness. Increases inexposure time (time in mold) will increase the depth of crystallinityand the overall percentage of crystallinity in the area, and changes inthe mold temperature in the region for which crystallinity is desiredwill affect the crystallinity rate and dimensional stability.

One of the many advantages of using the process disclosed herein is thatthe cycle times for the process are similar to those for the standardprocess to produce uncoated preforms; that is the molding and coating ofpreforms by this process is done in a period of time similar to thatrequired to make uncoated PET preforms of similar size by standardmethods currently used in preform production. Therefore, one can makebarrier coated PET preforms instead of uncoated PET preforms without asignificant change in production output and capacity.

If a PET melt cools slowly, the PET will take on a crystalline form.Because crystalline polymers do not blow mold as well as amorphouspolymers, a preform comprised of a body portion of crystalline PET wouldnot be expected to perform as well in forming containers as one having abody portion formed of PET having a generally non-crystalline form. If,however, the body portion is cooled at a rate faster than the crystalformation rate, as is described herein, crystallization of the PET willbe minimized and the PET will take on an amorphous or semi-crystallineform. Thus, sufficient cooling of the PET in the body portion of thepreform is crucial to forming preforms which will perform as needed whenprocessed.

The rate at which a layer of PET cools in a mold such as describedherein is proportional to the thickness of the layer of PET, as well asthe temperature of the cooling surfaces with which it is in contact. Ifthe mold temperature factor is held constant, a thick layer of PET coolsmore slowly than a thin layer. This is because it takes a longer periodof time for heat to transfer from the inner portion of a thick PET layerto the outer surface of the PET which is in contact with the coolingsurfaces of the mold than it would for a thinner layer of PET because ofthe greater distance the heat must travel in the thicker layer. Thus, apreform having a thicker layer of PET needs to be in contact with thecooling surfaces of the mold for a longer time than does a preformhaving a thinner layer of PET. In other words, with all things beingequal, it takes longer to mold a preform having a thick wall of PET thanit takes to mold a preform having a thin wall of PET. The temperaturecontrol system with the valves proximate to the preform can rapidly coolthe preform to minimize the cooling time for thick wall or thin wallPET.

The uncoated preforms, including those made by the first injection inthe above-described apparatus, are preferably thinner than aconventional PET preform for a given container size. This is because inmaking the barrier coated preforms, a quantity of the PET which would bein a conventional PET preform can be displaced by a similar quantity ofone of the preferred barrier materials. This can be done because thepreferred barrier materials have physical properties similar to PET, asdescribed above. Thus, when the barrier materials displace anapproximately equal quantity of PET in the walls of a preform orcontainer, there will not be a significant difference in the physicalperformance of the container. Because the preferred uncoated preformswhich form the inner layer of the barrier coated preforms arethin-walled, they can be removed from the mold sooner than theirthicker-walled conventional counterparts. For example, the uncoatedpreform can be removed from the mold preferably after about 4-6 secondswithout the body portion crystallizing, as compared to about 12-24seconds for a conventional PET preform having a total wall thickness ofabout 3 mm. All in all, the time to make a barrier coated preform isequal to or slightly greater (up to about 30%) than the time required tomake a monolayer PET preform of this same total thickness.

Additionally, because the preferred barrier materials are amorphous,they will not require the same type of treatment as the PET. Thus, thecycle time for a molding-overmolding process as described above isgenerally dictated by the cooling time required by the PET. In theabove-described method, barrier coated preforms can be made in about thesame time it takes to produce an uncoated conventional preform.

The advantage gained by a thinner preform can be taken a step farther ifa preform made in the process is of the type in FIG. 4. In thisembodiment of a coated preform, the PET wall thickness at 70 in thecenter of the area of the end cap 42 is reduced to preferably about ⅓ ofthe total wall thickness. Moving from the center of the end cap out tothe end of the radius of the end cap, the thickness gradually increasesto preferably about ⅔ of the total wall thickness, as at referencenumber 68 in the wall portion 66. The wall thickness may remain constantor it may, as depicted in FIG. 4, transition to a lower thickness priorto the support ring 38. The thickness of the various portions of thepreform may be varied, but in all cases, the PET and barrier layer wallthicknesses must remain above critical melt flow thickness for any givenpreform design.

Using preforms 60 of the design in FIG. 4 allows for even faster cycletimes than that used to produce preforms 50 of the type in FIG. 3. Asmentioned above, one of the biggest barriers to short cycle time is thelength of time that the PET needs to be cooled in the mold followinginjection. If the body portion of a preform comprising PET has notsufficiently cooled before it is ejected from the core, it will becomesubstantially crystalline and potentially cause difficulties during blowmolding. Furthermore, if the PET layer has not cooled enough before theovermolding process takes place, the force of the barrier materialentering the mold will wash away some of the PET near the gate area. Thepreform design in FIG. 4 takes care of both problems by making the PETlayer thinnest in the center of the end cap region 42, which is wherethe gate is in the mold. The thin gate section allows the gate area tocool more rapidly, so that the uncoated PET layer may be removed fromthe mold in a relatively short period of time while still avoidingcrystallization of the gate area and washing of the PET during thesecond injection or overmolding phase.

The physical characteristics of the preferred barrier materials help tomake this type of preform design workable. Because of the similarity inphysical properties, containers having wall portions which are primarilybarrier material can be made without sacrificing the performance of thecontainer. If the barrier material used were not similar to PET, acontainer having a variable wall composition as in FIG. 4 would likelyhave weak spots or other defects that could affect containerperformance.

D. Formation of Preferred Containers by Blow Molding

The containers are preferably produced by blow-molding preforms, thecreation of which is disclosed above. The mold 80 of FIG. 6 can compriseone or more temperature control systems 710. The illustrated mold 80comprises a blow mold neck portion 706 and a blow mold body portion 708.The temperature control system 710 can comprise a single or multicircuit system. The illustrated temperature control system 710 comprisesa plurality of temperature control elements in the form of channels 712,714, although other temperature control elements can be used. The fluidcirculation in the channels 712 is preferably independent from the fluidcirculation in the channels 714. The channels 712 pass through the blowmold neck portion 706, and the channels 714 pass through the blow moldbody portion 708. However, the channels can be at any suitable locationfor controlling the temperature of the blow molded container. The blowmold temperature control system can also comprise heating/cooling rods,electric heaters, and the like.

The mold 80 can comprise high heat transfer material to rapidly cool themolded container, thus reducing the amount of chilled air (e.g., foodgrade air) used to reduce the temperature of the container, althoughchilled air can be blown into the container to further reduce thetemperature of the container. For example, at least a portion of theblow molding interior surface 718 can comprise high heat transfermaterial. In some embodiments, high heat transfer material form at leastabout 10%, 40%, 60%, 80%, 90% and ranges encompassing these amounts ofthe interior surface. In some embodiments, the entire interior surface718 comprises high heat transfer material. The high heat transfermaterial can rapidly change the temperature of the blow molded containerwhen the container contacts the interior surface 718.

The blow mold 80 can be substituted with the molding apparatuses of thetemperature control systems described above. As such, variousconfigurations of fluid systems and working fluids can be employed withblow molds. Additionally, one or more pressure reducing elements can bein fluid in communication with the fluid channels 712, 714. The pressurereducing elements can vaporizes an effective amount of refrigerant(e.g., cryogenic fluids) to reduce the temperature of the cryogenicfluid such that the cryogenic fluid can sufficiently cool the blowmolded container within the mold cavity. Once the container contacts theinterior surface 718, the wall of the blown container can be quicklycooled to form a dimensionally stable wall of the container.

In other preferred embodiments in which it is desired for the entirecontainer to be heat-set, it is preferred that the containers beblow-molded in accordance with processes generally known for heat setblow-molding, including, but not limited to, those which involveorienting and heating in the mold, and those which involve steps ofblowing, relaxing and reblowing. The mold 80 can quickly cool thecontainer during this process, especially with high heat transfermaterial absorbing heat from the container at a high rate.

In some embodiments, the mold 80 can be used to produce crystalline neckfinishes. For example, the blow mold neck portion 706 and the blow moldbody portion 708 can selectively control the temperature of thepreform/container to achieve a desired amount of crystallization. Thus,the neck portion of the preform/container can be heated and graduallyreduced in temperature to produce a desired amount of crystallinematerial. To enhance thermal isolation, inserts 750 may be used toreduce heat transfer between portions of the mold 80. The illustratedinserts 750 are positioned between the blow mold neck portion 706 andthe blow mold body portion 708 and can be formed of an insulator.

In some embodiments for preforms in which the neck finish is formedprimarily of PET, the preform is heated to a temperature of preferably80° C. to 120° C., with higher temperatures being preferred for theheat-set embodiments, and given a brief period of time to equilibrate.After equilibration, it is stretched to a length approximating thelength of the final container. Following the stretching, pressurizedair, such as chilled food grade air, is forced into the preform whichacts to expand the walls of the preform to fit the mold in which itrests, thus creating the container. Working fluid is circulated throughthe channels 712, 714 and rapidly cools the container contacting theinterior surface 718. The temperature of the chilled air for stretchingthe preform and the temperature of the working fluid cooling theinterior surface 718 can be selected based on the desired containerfinish, production time, and the like.

FIG. 6A illustrates another embodiment of the mold for stretch blowmolding preforms. The blow mold body portion 708 a comprises an innerportion 740 and an outer portion 742. The inner portion 740 and theouter portion 742 can comprise materials with different thermalconductivities. The inner portion 740 defines blow molding interiorsurface 718 a and preferably comprises a high heat transfer material. Achilled fluid, such as a refrigerant, can be passed through the channels710 a to rapidly cool the blow molded container. The outer portion 742can form a thermal barrier to reduce heat transfer to the surroundingenvironment. The outer portion 742 surrounds the inner portion 740 tothermally isolate the inner portion 740. The outer portion 742 cancomprise steel or other thermally insulating material in comparison tothe material forming the inner portion 740.

The mold neck portion 706 a can comprise a neck portion 746 and an upperneck portion 748. The neck portion 746 preferably comprises high heattransfer material. The upper neck portion 748 can comprise an insulatingmaterial to thermally isolate the internal portions of the mold 80 asimilar to the body portion 708 a.

The temperature of the interior surfaces of the blow molds 80, 80 a canbe selected based on the preform design. For example, the temperaturesof the interior mold surfaces can be different for blow molding preformscomprising an outer layer of foam material and for blow molding preformscomprising an outer layer of PET. Although the blow mold 80 is discussedprimarily with respect to stretch blow molding a preform, the mold 80can be an extrusion blow mold. Thus, it is contemplated that the mold 80can be used for an extrusion blow molding process. Additionally, theembodiments, features, systems, devices, materials, methods andtechniques described herein may, in some embodiments, be similar to anyone or more of the embodiments, features, systems, devices, materials,methods and techniques described in U.S. patent application Ser. No.11/108,607 entitled MONO AND MULTI-LAYER ARTICLES AND EXTRUSION METHODSOF MAKING THE SAME, filed on Apr. 18, 2005 which is incorporated hereinby reference in its entirety.

E. Compression Methods and Apparatuses for Making Preferred Articles

Monolayer and multilayer articles (including packaging such as closures,preforms, containers, bottles) can be formed by a compression moldingprocess. As discussed above, one method of producing multi-layeredarticles is referred to herein generally as overmolding. The name alsorefers to a procedure which uses compression molding to mold one or morelayers of material over an existing layer, which preferably was itselfmade by a molding process, such as compression molding.

One overmolding method for making articles involves using a melt sourcein conjunction with a mold comprising one or more cores (e.g., mandrels)and one or more cavity sections. The melt source delivers a first amountof moldable material (e.g., a molten polymer (i.e., polymer melt)) tothe cavity section. A first portion of an article is molded between thecore and the cavity section. The first portion (e.g., a substrate layer)remains in the cavity section when the core is pulled out of the cavitysection. A second amount of material is then deposited onto the interiorof the first portion of the article. A second core is used to mold thesecond amount of material into a second portion of the article, thusforming a multi-layer article. This process may be referred to as“compress-over-compress.”

In one embodiment of compress-over-compress a melt source deposits afirst moldable material into a cavity section. A first portion (e.g., asubstrate layer) of articles is molded between a core and the firstcavity section. The first layer remains on the core when the core ispulled out of the first cavity section. A second moldable material isthen deposited into a second cavity section in order to make an exteriorportion of the article. The core and the corresponding first portion arethen inserted into the second cavity section. As the core and the firstlayer are moved into the second cavity section, the second material ismolded into a second portion of the article. The core and theaccompanying article are then removed from the second cavity section andthe article is removed from the core.

Thus, the overmolding method and apparatus can be used to mold innerlayers and/or outer layers of articles as desired. The multilayerarticles can be containers, preforms, closures, and the like.Additionally, one or more compression systems can be employed to formmultilayer articles. Each compression system can be a compression moldhaving cavity sections and cores that are used to mold a portion of anarticle. A transport system can transport articles between each paircompression molding systems. Thus, a plurality of compression moldingsystems can be used for an overmolding process.

In an especially preferred embodiment, the compress-over-compressprocess is performed while the first portion, e.g. a substrate layer,has not yet fully cooled. The underlying layer may have retainedinherent heat from a molding process that formed the underlying layer.In some embodiments, the underlying layer can be at room temperature orany other temperature suitable for overmolding. For example, articles atroom temperature can be overmolded with one or more layers of material.These articles may have been stored for an extended period of timebefore being overmolded.

Molding may be used to place one or more layers of material(s) such asthose comprising lamellar material, PP, foam material, PET (includingrecycled PET, virgin PET), barrier materials, phenoxy typethermoplastics, combinations thereof, and/or other materials describedherein over a substrate (e.g., the underlying layer). In somenon-limiting exemplary embodiments, the substrate is in the form of apreform, preferably having an interior surface for contacting foodstuff.

Articles made by compression molding may comprise one or more layers orportions having one or more of the following advantageouscharacteristics: an insulating layer, a barrier layer, a foodstuffcontacting layer, a non-flavor scalping layer, a high strength layer, acompliant layer, a tie layer, a gas scavenging layer, a layer or portionsuitable for hot fill applications, a layer having a melt strengthsuitable for extrusion. In one embodiment, the monolayer or multi-layermaterial comprises one or more of the following materials: PET(including recycled and/or virgin PET), PETG, foam, polypropylene,phenoxy type thermoplastics, polyolefins, phenoxy-polyolefinthermoplastic blends, and/or combinations thereof. For the sake ofconvenience, articles are described primarily with respect to preforms,containers, and closures.

The temperature control systems described above can comprise a moldingapparatus configured to mold articles (e.g., monolayer and multilayerarticles) by a compression molding process. FIG. 25 illustrates amolding system 1500 designed to make preforms that comprise one or morelayers. In the illustrated embodiment, the molding system 1500 is acompression molding system and comprises a melt source 1502 configuredto deliver moldable material to a turntable 1504 that has cavityportions 1508 with one or more mold cavity sections 1506 (FIG. 26).

The core section 1510 can cooperate with a corresponding cavity section1506 to mold the moldable material. The illustrated core section 1510(FIG. 26) has a core 1512 sized and adapted to be inserted into acorresponding cavity section 1506. The core 1512 can be moved between anopen position and a closed position. The illustrated core section 1512 ais in a closed position.

The source 1502 can feed melt material into the mold cavity section 1506from above or through an injection point along the mold cavity section1506. The term “melt material” is a broad term and may comprise one ormore of the materials disclosed herein. In some embodiments, meltmaterial may be at a temperature (e.g., an elevated temperature)suitable for compression molding. As shown in FIG. 27, the source 1502can produce and/or deliver melt material to the mold cavity sections1506 of the turntable 1504. The turntable 1504 can rotate about acentral axis to move the mold cavity sections 1506 into position suchthat the source 1502 can fill a portion of a mold cavity section 1506with melt for subsequent compression molding. The turntable 1504 and themold core section 1510 can continuously or incrementally rotate aboutthe center of the turntable 1504. Preferably, the core section 1510 andthe turntable 1504 move in unison for a portion of the molding processas discussed below.

As shown in FIG. 26, the mold core 1510 has a core 1512 that isconfigured to cooperate with the turntable 1504 to mold the meltmaterial. The core 1512 is configured and sized so that the core 1512can be advanced into and out of a corresponding mold cavity section1506. The core 1512 is designed to form the interior of a preform. Theillustrated core 1512 is an elongated body that has a base end 1548(FIG. 28). The core 1512 has a generally cylindrical body that tapersand forms the rounded based end 1548. The core 1512 can have a coremolding surface 1513 for molding melt. The core section 1510 can beconnected to a turntable or other suitable structure for moving the coresection 1510.

The mold cavity sections 1506 can be evenly or unevenly spaced along theturntable 1504. The illustrated cavity sections 1506 are designed tomold the exterior of a preform. The molding system 1500 can have one ormore circular arrangements of mold cavity sections 1506 that arepreferably disposed near the periphery of the turntable 1504. In theillustrated embodiment of FIG. 25, the turntable 1504 has one circulararrangement of mold cavity sections 1506.

The source 1502 is adapted to produce a melt stream suitable formolding. The source 1502 can output foam material, PET, lamellarmaterial, PP, or other moldable materials. In the illustratedembodiment, the melt from the source 1502 can be deposited into one ormore of the mold cavity sections 1506 and then molded by compressionmolding.

With reference to FIG. 27, the mold cavity section 1506 can have amovable neck finish mold for molding the neck finish of a preform. Inone embodiment, the mold cavity section 1506 comprises a movable neckfinish mold 1520 that has a neck molding surface 1522 configured to formthe neck portion of a preform and a body molding surface 1524 configuredto form the body portion of the preform. The neck finish mold 1520comprises a plurality of temperature control elements 1521 in the formof channels. The neck finish mold 1520 can be similar or identical tothe neck finish molds described above. The neck finish mold 1520 can beused to produce non-crystalline and crystalline neck finishes. In someembodiments, the neck finish mold 1520 comprises high heat transfermaterial to increase through-put of the molding system. Of course, aworking fluid (e.g., a refrigerant) can flow through the channels 1521of the neck finish mold 1520 for rapid temperature changes.

The neck finish mold 1520 is movable between one or more positions. Inthe illustrated embodiment, the neck finish mold 1520 is located in amolding position so that the neck molding surface 1522 cooperates withthe body molding surface 1524 of the molding body 1529 to form a moldingsurface 1525. The neck finish mold 1520 can be moved outward to a secondposition, in which the outer surface 1324 of the neck finish mold isproximate to or contacts the stop 1527. When the neck finish mold 1520is in the second position, a preform formed within the mold cavitysection 1506 can be ejected therefrom. After the preform has beenremoved from the mold cavity section 1506, the neck finish mold 1520 canthen be moved back to the illustrated first position so that anotherpreform can be formed.

The mold body 1529 can have one or more temperature control elements forcontrolling the temperature of the polymer. The illustrate mold body1529 comprises a plurality of temperature control elements 1541 in theform of channels for circulating fluid through the mold body 1529. Aworking fluid can be passed through the channels 1541 to control thetemperature of the material positioned within the mold.

FIG. 28 illustrates the core section 1510 positioned above acorresponding cavity section 1508 defining the mold cavity section 1506.The core section 1510 can be moved along a line of action 1532 in thedirection indicated by the arrows 1534 until the core section 1510 mateswith the cavity section 1508. As shown in FIGS. 29 and 29A, the coresection 1510 and the cavity section 1508 cooperate to form a space orcavity 1536 having the desired shape of a preform. After material hasbeen deposited into the mold cavity section 1506, the core section 1510can be moved from the open position of FIG. 28 to the closed position ofFIG. 29 in order to compress the melt such that the melt substantiallyfills the space or cavity 1536 (FIG. 29A). To cool the polymer, aworking fluid (e.g., a refrigerant) can be passed through pressurereducing elements 1356 and through the channels 1541 to cool thematerial in the mold.

In operation, the turntable 1504 can be positioned so that one of themold cavity sections 1506 is located below the output 1530 of the source1502 as shown in FIGS. 25 and 27. A plug or shot of melt is deliveredout of the opening 1538 of the output 1530 such that the plug falls intothe mold cavity section 1506. Preferably, the plug drops to the end caparea 1539 (FIG. 27) of the mold cavity section 1506.

The plug 1544 may comprise a plurality of layers. The plug 1544 maycomprise lamellar material in any desirable orientation for subsequentcompression molding. For example, one or more of the layers of the plug1544 can be horizontally oriented, vertically oriented, or in any otherorientation such that resulting preform made from the plug 1544 has adesired microstructure. In the illustrated embodiment of FIGS. 27 and28, many or most of the layers of the plug 1544 are generallyperpendicular to the line of action 1532. In some embodiments, the plug1544 comprises material without any orientation. For example, the plug1544 may comprise a substantially isotropic material.

The plug 1544 can be at any suitable temperature for molding. In someembodiments, the temperature of the plug 1544 is generally above theglass transition temperature (T_(g)) of at least one of the materialsforming the plug 1544, especially if the plug 1544 comprises lamellarmaterial. Preferably, a substantial portion of the material forming theplug 1544 is at a temperature that is generally above its glasstransition temperature (T_(g)). In other embodiments, the temperature ofthe plug 1544 is in the range of about the T_(g) to the melt temperature(T_(m)) of a substantial portion of the material forming the plug. Inother embodiments, the temperature of the plug 1544 is in the range ofabout T_(g) to about T_(m) of most of the material forming the plug. Insome embodiments, the temperature of the plug 1544 is generally abovethe T_(m) of at least one of the materials forming the plug 1544.Preferably, the temperature of the plug 1544 is generally above theT_(m) of a substantial portion of the materials forming the plug 1544. Askilled artisan can determine the appropriate temperature of the plug1544 delivered from the source 1502 for compression molding.

The turntable 1504 can be rotated about its center such that the filledmold cavity sections 1506 are moved about the center of the turntable1504 and the core section 1510 can be moved downwardly along the line ofaction 1532.

After the core section 1510 has moved downward a certain distance, itwill contact the upper surface 1546 of the plug 1544. As the base end1548 of the core 1512 advances into the plug 1544, the plug 1544 spreadsto generally fill the entire cavity section 1536. The plug 1544preferably comprises sufficient material to generally fill the entirecavity section 1536 as shown in FIG. 29A. The mold may or may not bepreheated to facilitate the flow of the polymer material between thecore section 1510 and the cavity section 1536.

With reference to FIGS. 29 and 29A, the core section 1510 is in theclosed position so that the lower surface 1550 of the core section 1510engages or contacts the upper surface 1551 of the cavity section 1506.The core section 1510 and the cavity section 1506 can have channels 1541that can remove heat from the material forming the preform 30 disposedwithin the cavity section 1536. To reduce cycle times, a refrigerant canflow through the channels 1541 to rapidly cool the melt. The refrigerantcan be a two-phase mixture for increased thermal load capabilities. Thecore section 1510 and/or the cavity section 1506 may or may not comprisehigh heat transfer that may work in combination with the working fluidto achieve rapid temperature changes.

After the preform has been sufficiently cooled, the core section 1510can be moved upwardly along the line of action 1532 to the open positionso that the preform can be removed from the mold cavity section 1506.Ejector pins or other suitable devices can be used to eject the preformfrom the mold cavity section 1506. Preferably, before the preform isejected from the mold cavity section 1506, the neck finish mold 1520 ismoved radially away from the preform to the second position, such thatthe preform can be conveniently and easily moved vertically out of themold cavity section 1506. In some embodiments, pulse cooling can beemployed to limit the formation of condensation on the molding surfaces.

The preform is formed within the cavity section 1536 at some point afterthe source 1502 deposits material into the mold cavity section 1506 andbefore the mold cavity section 1506 is rotated around and located onceagain beneath the output 1530 of the source 1502. Of course, the coresection 1510 and turntable 1504 preferably rotate in unison about thecenter of the turntable 1504 during the compression molding process. Thecore section 1510 can be attached to a complementary turntable similarto the turntable 1504. The two turntables can rotate together during themolding process.

Moldable material can also be disposed by other suitable means. FIG. 30illustrates a moldable material that can be delivered directly by aninjection molding process into a modified cavity section 1558. Thecomponents of the illustrated embodiment are identified with the samereference numerals as those used to identify the correspondingcomponents of the cavity section 1510 and turntable 1504 discussedabove.

The turntable 1504 comprises a feed system 1552 configured to delivermoldable material (e.g., foam, lamellar material, PP, PET, etc.)directly into the cavity section 1558. The feed system 1552 deliversmoldable material (e.g., melt) at any point along the cavity section1558 and preferably comprises the output 1530 of a source and a meansfor pushing material from the output 1530 into the cavity section 1558.

In one embodiment, the feed system 1552 comprises a push assembly 1560(e.g., a piston assembly) that is configured to push melt into thecavity section 1558. The push assembly 1560 can reciprocate between afirst position and a second position and has a plunger or piston 1562illustrated in a first position so that the upper surface 1564 of theplunger 1562 forms a portion of the cavity section 1558. Preferably, theupper surface 1564 forms the lower portion or end cap region of thecavity section 1558. The plunger 1562 can be moved from the illustratedfirst position to a second position 1563 (shown in phantom) forreceiving material from the output 1530. When the plunger 1562 is in thesecond position, the output 1530 feeds melt into a cylindrical chamberdefined by the tube 1566 and the upper surface 1564 of the plunger 1562.The plunger 1562 can be moved from the second position to the firstposition, thereby moving the material to the illustrated position. Inthis manner, material can be repeatedly outputted from the output 1530and into the chamber defined by the tube 1566 and then advanced into thecavity section 1558 for compression molding.

After the plug 1544 is positioned in the cavity section 1558, the core1512 can be advanced into the cavity section 1558 to compress and spreadthe material of the plug 1544 through the cavity 1536 in the mannerdescribed above. Preferably, the plug 1544 is molten plastic (e.g.,lamellar, PET, PP, foam, phenoxy type thermoplastic) that can be spreadeasily throughout the cavity 1536.

With reference to FIG. 31, the turntable 1604 can have a mold cavitysection 1568 that is generally similar to the mold cavities sectiondiscussed above. However, in the illustrated embodiment, the turntable1604 can have an injection system 1570 for injecting material into thecavity section 1568. The injection system 1570 can be configured toinject material at a desired location and/or with a desired orientation.In some embodiments, the injection system 1570 can be adjusted to injectmaterial at desired locations and/or with desired orientations.

In the illustrated embodiment, the turntable 1604 has an injectionsystem 1570 that is configured to inject a lamellar melt stream into thecavity section 1568 at a suitable points along the cavity sectionsurface. One or more injection systems 1570 can be used to inject alamellar melt stream at one or more locations along the mold cavitysection 1568. The injection system 1570 can inject a lamellar meltstream into a lower portion or end cap region of the mold cavity section1568. Alternatively, the injection system 1570 can inject a lamellarmelt into the upper portion of the mold cavity section 1568.

The injection system 1570 can comprise a gate 1572 at the downstream endof the output of the lamellar machine. The gate 1572 may selectivelycontrol the flow of the lamellar melt stream from the output 1530 into aspace or cavity section 1574 defined by the core 1580 and the cavitysection surface 1578 of the cavity section. The gate 1572 may comprise avalve system 1573 that selectively inhibits or permits the melt streaminto the cavity section 1568. In one embodiment, the injection system1570 injects material to form a plug (illustrated as a lamellar plug) atthe bottom of the cavity section 1568, similar to the plug shown in FIG.30. The plug can then be compressed by the core 1580 to form a preformwithin the cavity 1574.

One method of lamellar molding is carried out using modular systemssimilar to those disclosed in U.S. Pat. No. 6,352,426 B1 and U.S.application Ser. No. 10/705,748 filed on Nov. 10, 2003, the disclosuresof which are hereby incorporated by reference in their entireties andform part of this disclosure. In view of the present disclosure, askilled artisan can modify the methods and apparatus of the incorporateddisclosures for compression molding. For example, theinjection-over-injection (“101”) systems of the U.S. Pat. No. 6,352,426B1 can be modified for compression molding. For example, the melt ofthose systems can be injected into a mold cavity section and then thecore can be used to compress the melt to form a preform. Those systemscan be modified into compress-over-compress systems used to makemultilayer preforms formed by compression molding. Additionally, one ormore components, subassemblies, or systems, of these apparatuses can beemployed in the mold described herein. For example, the cavity sectionsand/or core sections of the molds disclosed herein may comprise highheat transfer material for enhancing thermal transfer withheating/cooling systems.

The compression molding system 1500 can be used to produce preforms thatcomprise non-lamellar materials (e.g., foam material, PET, PP, barriermaterial, combinations thereof, and other materials disclosed herein).Compression molding systems for making preforms comprising lamellarmaterial, and preforms comprising foam, can be similar to each other,except as further detailed below. That is, in some embodiments a foammelt can be molded in a similar manner as the lamellar materialdescribed herein. The temperature control elements of the mold can beused to precisely control the temperature and expansion of the foammaterial.

FIG. 25A illustrates a system 1591 comprising a plurality of subsystemsand is arranged to produce multilayer articles. Each of the subsystemscan have a temperature control system for controlling the temperature ofmolds. Generally, the system 1591 includes one or more systems (e.g.,compression systems, closure lining systems, etc.) and is configured toproduce multilayer articles, such as preforms, closures, trays, andother articles described herein. In some embodiments, the system 1591comprises a first system 1500 a connected to a second system 1500 b. Thefirst system 1500 a can be a compression molding system that molds afirst portion of an article, and the second system 1500 b can beconfigured to form a second portion of the article. The illustratedsystems 1500 a, 1500 b have turntables that rotate in thecounter-clockwise direction during a production process. A transportsystem 1599 can transport a substrate article from the first moldingsystem 1500 a to the second system 1500 b. Of course, additionalsubsystem(s) can be added to the system 1591. For example, the one ormore compression molding system similar to the compression moldingsystem 1500 can be connected to the system 1591. Thus, systems (similarto or different than the systems 1500, 1500 a, 1500 b, etc.) can beadded to the system 1591 to produce articles having more than twolayers, to place liners in multilayer closures, and the like.

The illustrated system 1591 comprises a first molding system 1500 a thatcan be similar to or different than the molding systems describedherein, such as the molding system 1500 of FIG. 25. The first moldingsystem 1500 a can have a plurality of cavity sections 1506 a configuredto mold substrate articles. The cavity sections 1506 a, 1506 b arearranged in a substantially circular pattern. The first molding system1500 a can deliver the substrate articles to the transport system 1599.

The illustrated transport system 1599 can carry substrates produced bythe first compression molding system 1500 a to the second system 1500 b.The transport system 1599 carries and delivers the substrates to thesecond system 1500 b, which can be a compression molding system. Thetransport system 1599 can comprise one or more of the following: handoffmechanisms, conveyor systems, starwheel systems, turrets, and the like.The illustrated transport system 1599 is positioned between the systems1500 a, 1500 b.

The second system 1500 b in some embodiments can form an outer layerover the substrate delivered by the transport system 1599. For example,the transport system 1599 can deliver substrate preforms to a core (notshown) of the molding system 1500 b. The source 1519 b can deposit meltinto the cavity section 1506 b, and the core holding the substrate canbe advanced into the cavity section 1506 b to mold the melt therein. Thecores and the cavity sections 1506 b can rotate continuously during theproduction process. The cavities of the cavity section 1506 b can belarger than the cavities of the cavity sections 1506 a in order to forman outer layer on the article. For example, the system 1591 can beconfigured to mold the preform 50 of FIG. 3. The first system 1500 a canform the inner layer 54 of the preform 50. The transport system 599 canremove the inner layer 14 and deliver the inner layer 54 to the secondsystem 1500 b. The second system 1500 b can have a holder (e.g., a core)that holds the inner layer 54. The cavity sections 1506 b can be rotatedand moved under the source 1519 b to receive melt. After melt has bedelivered into a cavity section 1506 b, the core and the inner layer 54can be advanced into the cavity section 1506 b, which can be similar tothe cavity sections 1568 of FIG. 33, to form the outer layer 52 of thepreform 50. The outer surface of the layer 54 and the cavity section1506 b cooperate to mold the melt. Of course, the system 1591 can bemodified to form the other preforms described herein.

In some embodiments, the transport system 1599 can place the substratepreform in the cavity section 1506 b. Melt can be deposited by thesource 1519 b into the interior of the substrate preform. A core (notshown) of the second system 1500 b can be advanced into substratelocated within the cavity section 1506 b to mold the melt. Thus, thesecond system 1500 b can mold a layer over the substrate produced by thefirst molding system 1500 a. The system 1591 can therefore be acompress-over-compress system for producing multilayer articles.

The system 1591 can be configured to produce other articles such asmultilayer closures. The first system 1500 a can mold at least a portionof a closure (e.g., a closure comprising lamellar material, foam, and/orother materials described herein). The transport system 1599 can receivethe at least a portion of a closure and deliver the at least a portionof the closure to the second system 1599. The second system 1599 can bea spraying system that sprays material onto the closure, lining system(e.g., a spray lining system, a spin lining system, insertion system,etc.), compression molding system, and the like. For example, the secondmolding system 1500 b can comprise systems or employ techniques similarto those disclosed in U.S. Pat. No. 5,259,745 to Murayama and U.S. Pat.No. 5,542,557 to Koyama et al., which are incorporated by reference intheir entireties.

FIG. 32 shows a compression molding system 1590 configured to moldmulti-layer articles in the form of preforms. The compression moldingsystem 1590 can be a compress-over-compress processing machine.Generally, the system 1590 can comprise one or more material sourcesconfigured to deliver material to the mold cavity sections 1508 of theturntable 1569. In the illustrated embodiment, the molding system 1590comprises a pair of material sources configured to output melt streamsinto the mold cavity sections 1506. For example, in the illustratedembodiment, the system 1590 can comprise a pair of melt machines thatcan be similar or different from each other. The molding system 1590 canalso comprise one or more ejector systems 1580 configured to remove thecompletely formed preforms from the turntable 1569.

As shown in FIG. 33, the core section 1568 has a core 1582 that isconfigured to be disposed within a corresponding mold cavity section1568 and can have various sizes depending on the desired article formedthrough the compression molding process. For example, a plurality ofcompression molding steps can be performed, wherein each step forms adifferent layer of a preform. As the turntable 1569 rotates about itscenter, various cores can be inserted into the turntable 1569 atdifferent times to form various portions of the preforms as describedbelow.

With reference to FIG. 33, the core section 1568 and the cavity section1568 are in the closed position. The core 1582 and the mold cavitysection 1568 are configured to form a portion of a preform. The core1582 and mold cavity section 1568 cooperate to define a cavity 1585 inthe shape of the outer layer 52 of the preform 50 of FIG. 3. Meltmaterial can be placed in the mold cavity 1585 when the core section1568 is in the open position. The core 1582 and mold cavity section 1568can cooperate to compress the melt material to fill the cavity 1585 toform the outer layer 52 in the manner described above. A skilled artisancan determine the appropriate amount of material to deposit into themold cavity section 1568 to fill the cavity 1585 defined by the coresection 1568 and the mold cavity section 1568. A temperature controlsystem can deliver cooling fluid through the channel 1530 to cool thepreform.

After the outer layer 52 is formed, the core 1582 can be removed fromthe cavity 1584 while the layer 52 is retained in the cavity 1584.Another core can be used to mold another layer of material, which ispreferably molded over the layer 52. As shown in FIG. 34, another core(i.e., core 1612) can be used to mold melt over the layer 52.

The cavity section 1602 can be formed between the outer surface 1601 ofthe layer 52 and the outer surface 1213 of the core 1613. The core 1612may have a shape that is generally similar to the shape of the core1582. Preferably, however, the core 1612 is smaller than the core 1582so that the surface 1613 of the core 1612 is spaced from the layer 52when the core section 1610 is in the illustrated closed position. Thesize and configuration of the core 1512 can be determined by one ofordinary skill in the art to achieve the desired size and shape of thecavity 1602 which is to be filled with material to form a portion of thepreform.

In operation, the system 1590 can have a source 1502 that outputs meltand drops it into the mold cavity section 1568 disposed beneath theoutput 1530. After the mold cavity section 1506 with the plug rotates inthe direction indicated by the arrow 1593, the core 1582 can be advanceddownwardly and into the mold cavity section 1568. As the base end 1534of the core 1512 compresses the plug, the material spreads and proceedsupwardly along the cavity 1587 until the material substantially fillsthe entire cavity 1587. A cooling fluid can be run through a temperaturesystem 1530 within the core section 1568 and the turntable 1569 torapidly cool the material forming the outer layer 52. After the materialhas sufficiently cooled, the core section 1568 is moved upwardly so thatthe core 1582 moves out of the mold cavity section 1568.

With continued reference to FIG. 32, after the core section 1568 hasbeen moved to the open position, the turntable 1569 can be rotated inthe direction indicated by the arrow 1593 until the mold cavity section1506 is located under the second material source 1502 a. The source 1502a can output a melt stream from the output 1595 onto the interiorsurface 1601 (FIG. 34) of the outer layer 52. The turntable 1509 canthen rotate in the direction indicated by the arrow 1597 and the coresection 1610 can be inserted into the turntable 1509 to compresses andspread the melt throughout the cavity 1602. In this manner, this secondcompression process can form the inner layer 53 of the preform 50. Onceagain, the temperature control system 1530 can be used to rapidly andefficiently cool the preform 50 for subsequent removal. After the coresection 1610 has moved to the open position and the neck finish mold1520 is moved apart, the preform 50 can be conveniently liftedvertically out of the turntable 1509 by the ejector system 1580. Theprocess can then be repeated to produce additional multilayer preforms.

It is contemplated that any number of core sections, cavity sections,and sources of materials can be used in various combinations to formpreforms of different configurations and sizes. The preforms may havemore than two layers of material. Although not illustrated, there can beadditional cores that are used to form additional layers throughcompression molding. Additionally, the above compression process can beused to produce coatings or layers on conventional preforms.

Those of ordinary skill in the art will recognize that the mold cavitysections can be located in any structure suitable for molding. Forexample, the mold cavity sections 1506 can be located in a stationarytable. One or more extruders or melt sources and the cores can bemovable with respect to the mold cavity sections. Thus, an extruder canmove to each mold cavity sections and deposit melt within the cavitysection. The core section can then move into the corresponding core tomold the preform.

The molding system 1590 can be configured to make multi-layer preformsby the compress-over-compress process. In some embodiments, the moldingsystem 1590 can have a core 1582 that is configured to mate with themold cavity 1568 to form an inner portion of a preform, such as theinner layer 54 of the preform 50 of FIG. 3. In other words, the cavity1585 can be in the shape of the inner layer 54 of the preform 50. Meltcan be deposited into the cavity section 1568 and can then be compressedbetween the core 1582 and the cavity section 1568 to form the innerlayer 54. After the inner layer 54 has been formed, the core section1568 can be moved upwardly out of the cavity section 1568. When thecavity section 1568 is moved out of the cavity section 1568, the outerlayer 54 is preferably retained on the core 1582. The outer layer 54 andthe core 1582 can then be inserted into a second cavity, preferablyconfigured to mate with the outer surface of the outer layer 54 todefine a cavity in the shape of the outer layer 52 of the preform 50.Melt can be deposited into the second cavity section and then compressedas the core section 1568 and layer 54 are moved into the second cavity.Thus, the second material can be compressed into the shape of the outerlayer 52 of the preform 50. After the preform 50 has been formed, thecavity section 1568 can be moved upwardly out of the second cavity sothat the preform 50 can be removed. Thus, one or more layers of apreform can be positioned on a core and used to mold multiple layers ofa preform in one or more cavities section. In view of the presentdisclosure, a skilled artisan can select and modify the molds disclosedherein to make various preforms and other articles disclosed herein.

It is contemplated that articles of other shapes and configurations canbe molded through similar compression molding process. For example, FIG.35 illustrates a molding system 1630 that is configured to mold a monoor multilayer closures. The molding system 1630 is defined by a coresection 1632 having a core 1634 and a mold cavity section 1636. In oneembodiment, material is passed through the line 1639 and through thegate 1640 and into the cavity 1642 defined between the core 1634 and thecavity section 1636. The core half 1632 can be in the open position whenthe material is passed through the gate 1640. The core half 1632 canthen be moved to the closed position to mold the melt into the desiredshape of the closure. In the illustrated embodiment, the cavity 1642also optionally includes a portion 1644 for forming a band andconnectors between the body and the band of the closure. The mold 1630can optionally include neck finish molds 1644, 1646 (e.g., split rings)that can be moved apart allowing the core half 1632 to move out of thecavity section 1636.

Additional layers can be added to the closure by additional compressionmolding processes. For example, the substrate 1650 (FIG. 36) formed inthe cavity 1642 can be retained on the core 1634 and inserted into asecond cavity section 1652. The delivery system of the second cavitysection 1652 can deposit material out of a gate 1654 and into the cavitysection 1652, preferably when the core section 1632 and cavity section1652 are in the open position. The core half 1632 can be moved from theopen position to a closed position, while the substrate 1650 ispositioned on the core 1634, the outer surface of the substrate 1650acts as a molding surface to compress the melt between the substrate1650 and the surface 1655 of the cavity section 1652. The melt can bespread throughout the space 1657 defined between the substrate 1650 andthe surface 1655. After the closure has sufficiently cooled, the corehalf 1632 can be removed from the cavity section 1652. Optionally,additional layers of material can be molded onto the closure by asimilar compress-over-compress process. In view of the presentdisclosure, a skilled artisan can design the desired shape of thesystems and molds disclosed herein to make various types of articles andpackaging described herein. Multiple layer closures can also be formedby the compress-over-compress processes as described above. For example,the inner layer of the closure can be molded within the outer layer.

The system 1591 of FIG. 25A can be configured to produce multilayerclosures. The first system 1500A of FIG. 25A of the system 1591 can molda first layer of the closures in a similar manner as described withrespect to FIG. 35. The second system 1500B of FIG. 25A can mold anouter layer of the closure in a similar manner as described with respectto FIG. 36.

Other types of molding systems can be employed to form mono andmulti-layer articles. As described below, there are various systems thatcan be employed to deliver material to a compression molding system.Although the exemplary embodiments are disclosed primarily with respectto stationary mold cavities section, these systems can be used in rotarysystems, such as the turntable system described above. Additionally,described herein, certain embodiments, features, systems, devices,materials, methods and techniques described herein may, in someembodiments, be similar to any one or more of the embodiments, features,systems, devices, materials, methods and techniques described in U.S.patent application Ser. No. 11/108,342 entitled MONO AND MULTI-LAYERARTICLES AND COMPRESSION METHODS OF MAKING THE SAME, filed on Apr. 18,2005, which is hereby incorporated by reference in its entirety. Thetemperature control systems can be used to control the temperature ofthese compression molding systems.

1. Method and Apparatus of Making Crystalline Material

Molds (including compression and injection molds) can be used to producepreforms having a crystalline material. While a non-crystalline preformis preferred for blow-molding, a bottle having greater crystallinecharacter is preferred for its dimensional stability during a hot-fillprocess. Accordingly, a preform constructed according to preferredembodiments has a generally non-crystalline body portion and a generallycrystalline neck portion. To create generally crystalline and generallynon-crystalline portions in the same preform, one needs to achievedifferent levels of heating and/or cooling in the mold in the regionsfrom which crystalline portions will be formed as compared to those inwhich generally non-crystalline portions will be formed. The differentlevels of heating and/or cooling are preferably maintained by thermalisolation of the regions having different temperatures. In someembodiments, this thermal isolation between the thread split, coreand/or cavity interface can be accomplished utilizing a combination oflow and high thermal conduct materials as inserts or separate componentsat the mating surfaces of these portions.

The cooling of the mold in regions which form preform surfaces for whichit is preferred that the material be generally amorphous orsemi-crystalline, can be accomplished by chilled fluid circulatingthrough the mold cavity and core. In preferred embodiments, a moldset-up similar to conventional injection molding applications is used,except that there is an independent fluid circuit or electric heatingsystem for the portions of the mold from which crystalline portions ofthe preform will be formed.

The molding systems of FIGS. 25-36 can be configured to produce preformshaving crystalline material. In the illustrated the cavity section 1508includes the body mold 1529 comprising several channels 1541 throughwhich a fluid, preferably chilled water or a refrigerant, is circulated.The neck finish mold 1520 has one or more channels 1521 in which a fluidcirculates. The fluid and circulation of channels 1541 and channels 1521are preferably separate and independent.

The thermal isolation of the body mold 1529, neck finish mold 1520 andcore section is achieved by use of inserts or having low thermalconductivity. Examples of preferred low thermal conductivity materialsinclude heat-treated tool steel (e.g. P-20, H-13, Stainless etc.),polymeric inserts of filled polyamides, nomex, air gaps and minimumcontact shut-off surfaces.

In this independent fluid circuit through channels 1521, the fluidpreferably is warmer than that used in the portions of the mold used toform non-crystalline portions of the preform. Preferred fluids includewater, silicones, and oils. In another embodiment, the portions of themold which forms the crystalline portions of the preform, (correspondingto neck finish mold 1520) contain a heating apparatus placed in theneck, neck finish, and/or neck cylinder portions of the mold so as tomaintain the higher temperature (slower cooling) to promotecrystallinity of the material during cooling. Such a heating apparatuscan include, but is not limited to, heating coils, heating probes, andelectric heaters. Additional features, systems, devices, materials,methods and techniques are described in patent application Ser. No.09/844,820 (U.S. Publication No. 2003-0031814) which is incorporated byreference in its entirety and made a part of this specification.Additionally, the channels 1521 can be used to heat the molds and causeexpansion of foam material.

Although these inventions have been disclosed in the context of certainpreferred embodiments and examples, it will be understood by thoseskilled in the art that the present inventions extend beyond thespecifically disclosed embodiments to other alternative embodimentsand/or uses of the inventions and obvious modifications and equivalentsthereof. In addition, while several variations of the inventions havebeen shown and described in detail, other modifications, which arewithin the scope of these inventions, will be readily apparent to thoseof skill in the art based upon this disclosure. It is also contemplatedthat various combination or sub-combinations of the specific featuresand aspects of the embodiments may be made and still fall within thescope of the inventions. It should be understood that various featuresand aspects of the disclosed embodiments can be combined with orsubstituted for one another in order to form varying modes of thedisclosed inventions. Thus, it is intended that the scope of at leastsome of the present inventions herein disclosed should not be limited bythe particular disclosed embodiments described above.

1. A mold comprising: a core section having a core surface; a cavitysection having a cavity surface, a mold cavity being defined by the coresection and the cavity section when the mold is in a closed position; afluid channel being disposed within one of the core section and thecavity section; and a pressure reducing device configured to receive andvaporize at least a portion of a refrigerant, the pressure reducingdevice in fluid communication with the fluid channel; wherein said oneof the core section and the cavity section comprising high heat transfermaterial, the high heat transfer material being positioned between thefluid channel and the mold cavity.
 2. The mold of claim 1, wherein thehigh heat transfer material has a thermal conductivity at least twotimes greater than a thermal conductivity of iron.
 3. The mold of claim1, further comprising a plurality of fluid channels disposed within thecavity section and the high heat transfer material forms at least asubstantial portion of the cavity section which is interposed betweenthe plurality of fluid channels and the mold cavity.
 4. The mold ofclaim 1, wherein the cavity surface is defined by the high heat transfermaterial.
 5. The mold of claim 1, wherein the pressure reducing deviceis an expansion valve with a fixed diameter orifice.
 6. The mold ofclaim 1, wherein the refrigerant comprises substantially nitrogen orcarbon dioxide.
 7. The mold of claim 1, wherein the mold cavity isdefined by the cavity surface and the core surface, the cavity surfaceand the core surface each comprises high heat transfer material.
 8. Themold of claim 1, further comprising a first fluid channel, a secondfluid channel, and a fluid line, the fluid line is configured to receiveheated fluid that has passed through at least one of the first fluidchannel and the second fluid channel and delivers the heated fluid tothe first fluid channel, the second fluid channel is configured toreceive fluid, which has passed through the pressure reducing device andis cooler than the heated fluid.
 9. The mold of claim 1, furthercomprising a temperature control system configured to deliver fluidcomprising mostly refrigerant in a liquid state to the core section orthe cavity section and to receive fluid comprising mostly refrigerant ina gas state that has passed through a portion of the core section or thecavity section.
 10. The mold of claim 9, wherein the temperature controlsystem is an open loop system that vents the refrigerant to theatmosphere.
 11. The mold of claim 9, wherein the temperature controlsystem is a closed loop system.
 12. The molding of claim 1, wherein thehigh heat transfer material has a thermal conductivity greater thaniron.
 13. The mold of claim 1, wherein the cavity section furthercomprises a plurality of pressure reduction devices proximate to thecavity surface.
 14. The mold of claim 1, wherein the mold is one of acompression mold or an injection mold.
 15. A molding system, comprising:a first mold section and a second mold section movable between an openposition and a closed position, a mold cavity being defined between thefirst mold section and the second mold section when the first moldsection and the second mold section occupy the closed position, at leastone of the first mold section and the second mold section comprisinghigh heat transfer material and at least one fluid channel; a fluidsource in fluid communication with the at least one fluid channel, thefluid source containing refrigerant; and a pressure reducing element influid communication with the at least one fluid channel and the fluidsource, the pressure reducing element configured to reduce a pressure ofthe refrigerant from the fluid source to a second pressure equal to orless than a vaporization pressure of the refrigerant.
 16. The moldingsystem of claim 15, wherein the high heat transfer material has athermal conductivity at least two times greater than the thermalconductivity of iron.
 17. The molding system of claim 15, wherein therefrigerant comprises a cryogenic fluid.
 18. The molding system of claim15, wherein the first mold section and the second mold section form oneof a blow mold, injection mold, and a compression mold.
 19. The moldingsystem of claim 15, wherein the pressure reducing element vaporizes aneffective amount of the refrigerant to reduce the temperature of therefrigerant such that the refrigerant can sufficiently cool an articlewithin the mold cavity to form a dimensionally stable outer surface ofthe article suitable for demolding.
 20. The molding system of claim 15,wherein the pressure reducing element is positioned in the at least onefluid channel.
 21. The molding system of claim 15, further comprising: aheat exchanger in fluid communication with the at least one fluidchannel; a compressor configured to receive fluid from the at least onefluid channel and to output a pressurized fluid, the compressor ispositioned along a fluid path between the at least one fluid channel andthe heat exchanger; and a bypass system comprising a flow regulatingvalve, the bypass system being configured to convey pressurized fluidfrom the compressor to the flow regulating valve and to the pressureregulating element such that the pressurized fluid flows through thepressure reducing element and then into the at least one fluid channel.22. The molding system of claim 15, further comprising a second fluidsource containing a second fluid, the second fluid having a freezingpoint temperature that is greater than the temperature of therefrigerant from the first fluid source in the at least one fluidchannel.
 23. The molding system of claim 21, further comprising: atemperature sensor interposed between a molding surface of the at leastone of the first mold section and the second mold section and the atleast one fluid channel; and a controller in communication with thetemperature sensor, the controller is configured to selectively controlthe operation of the pressure reducing element and the flow regulatingvalve in response to a signal from the temperature sensor.
 24. Themolding system of claim 15, wherein the refrigerant comprises liquidselected from one of liquid carbon dioxide, liquid nitrogen, andcombinations thereof.
 25. The molding system of claim 15, wherein thepressure reducing element comprises a valve with a fixed orifice. 26.The molding system of claim 15, wherein the pressure reducing elementcomprises a valve with a variable opening.
 27. The molding system ofclaim 15, wherein the pressure reducing element comprises a nozzle valveor a needle valve.
 28. The molding system of claim 15, wherein the highheat transfer material comprises a hardened copper alloy having athermal conductivity at least twice a thermal conductivity of iron. 29.The molding system of claim 15, further comprising a plurality of fluidchannels for cooling melt disposed within the mold cavity and aplurality of fluid sources, each of the fluid channels is in fluidcommunication with at least one of the fluid sources, wherein the numberof fluid sources is less than the number of fluid channels.
 30. Themolding system of claim 15, wherein the at least one of the first moldsection and the second mold section comprises a plate, the platecomprising the at least one fluid channel, and a fluid line in fluidcommunication with the fluid source and the at least one fluid channel.31. The molding system of claim 30, wherein the at least one fluid lineis thermally insulated.
 32. The molding system of claim 15, wherein thefirst mold section comprises a core terminating at a core tip, the moldcavity is in the shape of a preform, and the pressure reducing elementis positioned within the core and near the core tip.
 33. The moldingsystem of claim 32, wherein a substantial portion of the core compriseshigh heat transfer material.
 34. The molding system of claim 32, whereinthe core comprises an upper core portion configured to mold a neckportion of a preform, the upper core portion comprises a first material,and the core tip comprises a second material having a thermalconductivity greater than a thermal conductivity of the first material.35. The molding system of claim 15, further comprising a neck finishmold positioned between the first mold section and the second moldsection, the neck finish mold comprising high heat transfer material.36. The molding system of claim 15, wherein the molding system is one ofan injection molding system, a compression molding system, and a stretchblow molding system.
 37. A mold for molding an article, the moldcomprising: a cavity section; and a core section being configured tomate with the cavity section to form a mold cavity, the core sectioncomprising a core defining an internal surface of the mold cavity, atube within the core extending from a proximal end of the core to apressure reducing valve at a distal end of the core, the pressurereducing valve configured to receive fluid from the tube and to deliverat least partially vaporized fluid to a channel within the core, whereinthe partially vaporized fluid in the core is at a temperature less thana temperature of the internal surface of the mold cavity when melt fillsthe mold cavity.
 38. The mold of claim 37, further comprising a neckfinish mold being configured to mold a neck portion of a preform, theneck finish mold being positioned between the cavity section and thecore section and comprising high conductivity material.
 39. The mold ofclaim 37, wherein the channel extends from the proximal end to thedistal end of the core and is between the tube and an outer wall of thecore.
 40. The mold of claim 37, wherein a portion of the core isconfigured to form a portion of the mold cavity and has a length todiameter ratio greater than about
 4. 41. The mold of claim 37, wherein aportion of the core is configured to form a portion of the mold cavityand has a length to diameter ratio greater than about
 6. 42. A moldassembly comprising: a core section; a cavity section defining a cavitysurface configured to mold at least a portion of an article, the cavitysection cooperates with the core section to form a space; a plurality offluid channels surrounds a portion of the cavity surface, the pluralityof fluid channels is positioned within a portion of the cavity sectionhaving a high thermal conductivity; and a valve system being locatedupstream of the fluid channels, the valve system receives cryogenicfluid at a first temperature and delivers the cryogenic fluid at asecond temperature, which is less than the first temperature, to theplurality of fluid channels.
 43. The mold assembly of claim 42, whereinthe cavity section comprises a first portion and a removable secondportion, the valve system comprises an insertable pressure reducingelement that is exposed when the second portion is removed from thecavity section.
 44. The mold assembly of claim 42, wherein the valvesystem comprises a plurality of expansion valves, and each expansionvalve is in fluid communication with at least one fluid channel.
 45. Themold assembly of claim 42, wherein the plurality of fluid channelscomprises fluid channels that are in fluid communication with eachother.
 46. The mold assembly of claim 45, further comprising a pluralityof fluid passages, each fluid passage extends between a pair of thefluid channels.
 47. The mold assembly of claim 42, further comprising aportion of the cavity section positioned between the plurality of fluidchannels and the cavity surface, wherein the portion of the cavitysection is formed of high heat transfer material.
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 55. A molding system, comprising: a first mold sectionand a second mold section movable between an open position and a closedposition, a mold cavity being defined between the first mold section andthe second mold section when the first mold section and the second moldsection occupy the closed position, the mold cavity having a shape of apreform; and a neck finish mold interposed between the first moldsection and the second mold section, the neck finish mold having a neckmolding surface configured to mold a portion of melt disposed in themold cavity, the neck finish mold comprising high heat transfer materialand a temperature control element configured to selectively control thetemperature of the neck molding surface, wherein the high heat transfermaterial is positioned between the neck molding surface and thetemperature control element.
 56. The molding system of claim 54, whereina substantial portion of the neck finish mold extending between thetemperature control element and the neck molding surface comprises highheat transfer material.
 57. The molding system of claim 56, wherein thehigh heat transfer material forms the neck molding surface, the neckmolding surface is dimensioned so as to form threads of a preform. 58.The molding system of claim 56, wherein a portion of the neck finishmold extends between the temperature control element and the neckmolding surface, wherein high heat transfer material forms at least 80%by weight of the portion of the neck finish mold.
 59. The molding systemof claim 58, wherein high heat transfer material forms at least 90% byweight of the portion of the neck finish mold.
 60. The molding system ofclaim 54, wherein the temperature control element comprises a pluralityof cooling channels disposed within the high heat transfer material. 61.The molding system of claim 54, wherein the neck finish mold is a splitring that is movable between a first position for molding a portion of apreform and a second position for demolding the preform.
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